IP Marking, Metering, and Management

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "IP Marking, Metering, and Management"

Transcription

1 ENSC 833 High Performance Networks IP Marking, Metering, and Management Jason Uy Alison Xu April 14, 2003 Dr. Ljiljana Trajkovic

2 Table of Contents TABLE OF CONTENTS... 2 LIST OF FIGURES... 4 LIST OF TABLES... 5 DEFINITIONS INTRODUCTION CABLE NETWORK DIFFERENTIATED SERVICE BACKGROUND NODE MODEL TRAFFIC CLASSIFICATION ASSURED FORWARDING SINGLE RATE THREE COLOR MARKER TYPE OF SERVICE PROCESS MODEL MANAGEMENT BLOCK DECISION PROCESS AF MONITOR PROCESS MULTIPLEXING PROCESS CONTROL PROCESS OUTPUT FIFO OUTGOING MONITOR PROCESS SIMULATION AF CLASS AF CLASS 2 TEST CASE

3 7.3 AF CLASS 3 TEST CASE AF CLASS 4 - TEST CASE CONCLUSION REFERENCES... 37

4 List of Figures Figure 1 Cable Network Topology... 8 Figure 2 Node Model...11 Figure 3 Single Rate Three Color Marking Algorithm Figure 4 Single Rate Three Color Marker Process Model Figure 5 Management Block Diagram Figure 6 Decision Process Model Figure 7 AF Monitor Node Process Mode Figure 8 Multiplexing Process Model Figure 9 Control Process Model Figure 10 Bandwidth Monitor Node Process Model Figure 11 Project Model Figure 12 Current Level of Decision Process Figure 13 Total Colored Packets for AF Class Figure 14 Total Dropped Packets for AF Class Figure 15 Bank's Packets Figure 16 Bank's Incoming and Outgoing Packets Comparison Figure 17 Current Level of Decision Process Figure 18 Total Colored Packets in AF Class Figure 19 Total Dropped Packets on AF Class Figure 20 Current State of AF Class 4 and Multiplexing Process Figure 21 Zoomed Diagram of Current State of AF Class 4 and Multiplexing Process Figure 22 Total Colored Packets and Total Dropped Packets of AF Class

5 List of Tables Table 1 Definition... 6 Table 2 Decision Process Level Definition Table 3 AF Monitor Process Bandwidth Usage Level Table 4 FIFO Usage Level Table 5 Control Process Truth Table... 22

6 Definitions The following table defines terms and abbreviations used in this document. Table 1 Definition AF CBS CIR CMTS DS EBS IP ISP PHB QoS TOS Assured Forward Committed Burst Size Committed Information Rate Cable Modem Termination System Differential Service Excess Burst Size Internet Protocol Internet Service Provider Per-Hop-Behavior Quality of Service Type of Service

7 1 Introduction High speed Internet Service Providers (ISPs) such as Shaw Cable offers shared bandwidth internet connection to thousands of subscribers within a neighborhood. In a shared network architecture, all subscribers compete for the available bandwidth that is allocated to their neighborhood by the service provider. It is therefore possible that a certain number of subscribers can collectively use most of the bandwidth of the neighborhood, leaving other users with a slower internet connection. In such a situation, applications that require certain Quality of Service (QoS) will not work reliably. To provide a certain guaranteed bandwidth to customers, this project will implement a Differentiated Service (DS) node that will guarantee user bandwidth, at the same time maximizing utilization of the ISP s backbone connection. This DS node has two main sections: Classification, and Management. The Classification section involves metering bandwidth usage and marking packets based on subscription contract. The Management section involves proper handling of the incoming packets to provide a fair dropping algorithm, while maintaining high utilization on the backbone connection. Simulation of traffic activity from a local neighborhood will be used to verify the implementation.

8 2 Cable Network Below is an illustration of how subscribers from different neighborhoods are connected to the ISPs core network. Figure 1 Cable Network Topology Neighborhood B Neighborhood C Cable Modem Termination System Neighborhood A CPE Modem Cable Modem Termination System Modem CPE Internet Provider Core Network Cable Modem Termination System Cable Modem Termination System Hybrid Fiber Coaxial Modem Modem... Modem CPE CPE CPE Cable Modem Termination System Neighborhood D Neighborhood E As seen in Figure 1, each cable modem, indicated as Customer Premises Equipment (CPE), is connected to a central hub that converts the electrical signals to optical signals. The central hub is usually located at the center of a neighborhood so that the distance from customer premises to the central hub is uniform. The optical signal is then carried to the Cable Modem Termination System (CMTS) using fiber optic cable. The combination of fiber optic and coaxial cable connection from the CMTS to the subscriber s cable modem is called a Hybrid Fiber Coaxial connection. This type of connection provides the best performance/cost ratio as it brings optical signal as close to the subscriber as possible, while utilizing the existing coaxial connections found in most homes. The CMTS takes in the data coming from each subscriber and decides whether to pass the packet to its backbone connection. A CMTS backbone connection connects to the Provider Core Network. The project s goal is to implement a CMTS to provide QoS to subscribers. Each CMTS is allocated a fixed bandwidth that the ISP network administrator deems adequate for the size of the neighborhood. Just like a telephone network, an ISP often oversubscribes its available bandwidth due to the fact that not all subscribers will be using the network at the same time. In the event that a large number of subscribers send traffic simultaneously through the cable network, the CMTS will need to decide which packets to drop based on each customer s subscription level and current bandwidth usage.

9 If a customer s bandwidth usage is within his/her subscription limit, the CMTS will guarantee transmission of all packets to the backbone connection. If a customer s bandwidth usage is greater than his/her subscription limit, the bandwidth that is over the subscription limit will be managed according to a best effort scheduling algorithm. With a QoS function implemented in the CMTS, service providers can provide different bandwidth subscriptions levels to customers to better optimize the network usage.

10 3 Differentiated Service Background There are three different types of Quality of Service (QoS): Best Effort, Guaranteed Service, and Differentiated Service. The Best Effort Service is the type of service that most ISPs currently provide. In this type of service, there are no guarantees in terms of bandwidth, latency, or delay for packet transmission given to a subscriber. This type of service is sufficient for non-real time applications such as sending/receiving s and browsing the Internet. The major advantage of this type of service is the cost. This service provides the ISP with the highest return on investment because the cost of the equipment required to deploy this type of service is the least expensive among the three different types of QoS. The major disadvantage of this type of service is the lack of bandwidth guarantee. When a subscriber transmits data, the probability of the packets being dropped depends on the current bandwidth usage of a neighborhood, instead of the current bandwidth usage of the subscriber. The Guaranteed Service provides a subscriber with a specific bandwidth, delay, and jitter on every packet that is transmitted. This is the best form of connection a subscriber can get as the bandwidth is always available. The bandwidth will never change regardless of the traffic usage of other subscribers in the same neighborhood. The main advantage of this type of service is the reliability in terms of guaranteed bandwidth. The main disadvantage of this type of service is the inefficiency of the backbone connection utilization. The Differentiated Service is a compromise between the Best Effort Service and the Guaranteed Service. In this type of service, ISPs provide a statistical preference to certain incoming packets depending on the monitored Committed Information Rate (CIR), Committed Burst Size (CBS), and Excess Burst Side (EBS). Every subscriber is assigned a value for each parameter (CIR, CBS, and EBS) depending on the subscription level or contract that was agreed upon by the subscriber and the service provider. One of the main advantages of this service is that the bandwidth is guaranteed most of the time if it conforms to the CIR, CBS, and EBS parameter designated by the service provider. The main disadvantage of this type of service is that the dropping probability of each packet, to a small degree, depends on the overall bandwidth usage of the neighborhood. This will be explained in detail in the next section. This type of QoS will be implemented for this project. For each QoS type, there are four parameters that can be focused on when providing services: bandwidth, end to end delay, packet jitter, and packet loss. For this project, the main emphases are on bandwidth and packet loss. These parameters were chosen as most cable subscribers are interested in how fast the download speed they are getting. Applications such as web browsers, ftp clients, and programs all rely on how fast data can be received. Other applications that are sensitive to end to end delay or packet jitter (e.g. video conferencing or voice over IP) are not included in the study conducted for this project.

11 4 Node Model The purpose of the CMTS is to take in packet coming from the subscriber, monitor the bandwidth usage and decide which packets to pass though and which packets to drop. The CMTS uses the node model shown in Figure 2 to implement this functionality. There are a total of 12 different processors used to implement the node model: Receiver Processor, Subscriber Bandwidth Monitor Processor, Classification Processor, Decision Processor, AF Class Processor, Multiplexing Processor, Control Processor, Output FIFO Processor, Outgoing Monitor Processor, Subscriber Output Bandwidth Monitor Processor, Output Director Processor, and Transmitter Processor. Figure 2 Node Model There are a total of seven receivers and seven transmitters in the model to represent seven different subscribers connected to the CMTS (all in the same neighborhood). The Receiver Processor passes received packets to the Subscriber Bandwidth Monitor Processor. This processor is included for the purpose of verification only. The processor monitors the incoming bandwidth coming from each subscriber so that the result can be compared to the results of the Outgoing Bandwidth Monitor Processor. After the subscriber bandwidth is monitored, the packets from the seven monitor processors are sent to four Assured Forwarding (AF) Classes. AF Classes mark incoming packets based on customer s subscription level and contract. Each AF Class is assigned a maximum bandwidth it can support. For example, an AF Class with a large allocation of bandwidth may be connected to business subscribers, while an AF Class with a small allocation of bandwidth may be connected to residential customers. In Figure 2, the first AF Class is composed of the first two Classification Processors (marker_ip0 and marker_ip1). The second AF Class is composed of the next two Classification Processors (marker_ip10 and marker_ip11). The last AF Class only has one subscriber connected to it, so the Class only has one Classification Processor (marker_ip30). The Classification Processors inside an AF Class mark each packet green, yellow, or red depending on how the subscriber meets

12 the CBS and EBS parameters assigned by the network administrator. Green packets indicate that the current usage is within the CBS parameter. Yellow packets indicate that the current usage is within the EBS parameter. Red packets indicate that the current usage has exceeded both EBS and CBS. The classification algorithm is described in detail in section 5. After packets are classified, they go through the Management block where packets are passed or dropped depending on the CMTS current state. There are six processors that make up the Management Block: Decision Processor, AF Monitor Processor, Multiplexing Processor, Control Processor, Output FIFO, and Outgoing Monitor Processor. There are a total of four Decision Processors in the Management Block. Each Decision Processor decides whether to drop the packets received or not depending on the current bandwidth usage of the AF Class and the Output FIFO size. Un-dropped packets are then sent to the AF Monitor Processors where the bandwidth for the entire AF Class is measured. The AF Monitor Processors use four different threshold levels to decide how much bandwidth is currently being used. The result of the bandwidth measurement is sent to the Control Processor. Packets are then sent from the AF Monitor Processors to the Multiplexing Processor. The Multiplexing Processor takes in packets from the different AF Monitor Processors and sends them to the Output FIFO. The Multiplexing Processor also sends the current Output FIFO size to the Control Processor. The Control Processor takes in bandwidth information from the AF Monitor Processors and Output FIFO size from the Multiplexing Processor to determine the appropriate dropping level commands to send to each Decision Processor. The Output FIFO, just like the AF Monitor Processors, uses four different threshold levels to determine the current Output FIFO size. Packets from the Output FIFO are then sent to the Outgoing Monitor Processor where the bandwidth is measured to ensure that the outgoing bandwidth does not exceed the specified backbone connection. The Management Block is discussed in detail in section 6. Packets coming from the Outgoing Monitor Processor then go through a Subscriber Output Bandwidth Monitor Processor where the bandwidth from each subscriber is monitored. This process is used for verification of the implementation. The Output Director Processor eventually receives the packets and sends it out to the appropriate Transmitter Processors.

13 5 Traffic Classification Traffic Classification involves metering to determine whether the current bandwidth usage is within certain parameters, and marking to give priorities to all the packets. Metering is done using the Assured Forwarding model, while marking is done using the Single Rate Three Color Marker algorithm. 5.1 Assured Forwarding Normally a subscriber wants assurance that its IP packets are forwarded with high probability as long as the subscribed information rate is not exceeded. If the subscribed information rate is exceeded, there is an understanding the excess traffic will not be delivered with as high probability as the traffic that is within the profile. This essentially provides different levels of forwarding assurances for IP packets. For this project, the Assured Forwarding (AF) Per-Hop-Behavior (PHB) group as described in RFC 597 Assured Forwarding PHB Group is implemented. There are four independent AF Classes defined for the CMTS. Each AF Class is allocated a configurable, minimum amount of forwarding resource (e.g. buffer space and bandwidth). An AF Class may also be configurable to receive more forwarding resources than the minimum when excess resources are available from other AF Classes. Within each AF Class, an IP packet can be marked one of the three different levels of drop precedence. In case of congestion, the drop precedence of a packet determines the relative importance of the packet within the AF Class. A congested CMTS tries to protect packets with a lower drop precedence value from being lost by preferably discarding packets with a higher drop precedence value. In a CMTS, the level of forwarding assurance of an IP packet depends on the following: The forwarding resource that has been allocated to the AF Class that the packet belongs to. The current load of the AF Class. The drop precedence of the packet during congestion within the Class. Subscribers who wishes to have QoS on their subscription will be assigned to one of these AF Classes. 5.2 Single Rate Three Color Marker The CMTS uses a marking scheme described in RFC 2697 A Single Rate Three Color Marker. It meters an IP packet stream and marks its packets according to three traffic parameters: Committed Information Rate (CIR) [bit/s], Committed Burst Size (CBS) [bit], and Excess Burst Size (EBS) [bit]. Marked packets are assigned either a green, yellow, or red color. A packet is marked green if it does not exceed the CBS, yellow if it does exceed the CBS, but not the EBS, and red otherwise. The marker can operate in one of two modes: the color-blind mode, and the color-aware mode. In coloraware mode the marker assumes that the incoming packets are already colored by another marker. In the color-blind mode, the marker assumes the incoming packets are uncolored. In this project, we implemented the color-blind Single Rate Three Color Marker (srtcm) algorithm. The meter is configured by setting values to three traffic parameters: CIR, CBS, and EBS. It is recommended that the value set for the CBS or the EBS is larger or equal to the size of the largest possible IP packet in the stream.

14 Figure 3 Single Rate Three Color Marking Algorithm Received an IP packet Update Tc and Te credits bucket 0 PSize>Tc? n Tc=Tc-Psize y bucket 1 PSize>Te? n Te=Te-Psize y Green Yellow Red End The srtcm marking algorithm is illustrated in Figure 3 above. It features two token buckets, bucket 0 and bucket 1, which both share the common rate CIR. The maximum size of the token bucket 0 is CBS, and the maximum size of the token bucket 1 is EBS. The token buckets 0 and 1 are initially full at time 0. Namely the token count Tc(0) = CBS and the token count Te(0) = EBS. Thereafter, the token counts Tc and Te are decremented whenever a new IP packet arrives at the CMTS. The token counts are incremented when new credits are received. New credits are accumulated using the formula Credit = CIR * t. The Credit will be used to fill bucket 0 first, and any leftover will be used to fill bucket 1. After both bucket 0 and bucket 1 are filled, any additional credits are discarded. The following pseudo code explains how the algorithm works when a packet arrives if (Tc(t) Psize >= 0) { # mark packet green Tc = Tc Psize } else if (Te(t) Psize >= 0) { # mark packet yellow Te = Te Psize

15 } else { # mark packet red } 5.3 Type of Service Below is the summary of the contents of the Internet Protocol version 4 (IPv4) header: Version IHL Type of Service Total Length Identification Flags Fragment Offset Time to Live Protocol Header Checksum Source Address Destination Address Options Padding There is an 8 bit wide field called Type of Service (TOS). The field provides an indication of the type of quality of service desired. This field is to be used to guide the selection of the actual service parameters when transmitting a datagram through a particular network. The network can offer service precedence. For example, treat high precedence traffic as more important than other traffic. The major choice is a three way tradeoff between low-delay, high reliability, and high-throughput. Precedence D T R 0 0 Bit 0-2: Precedence. 111 Network Control 110 Internetwork Control 101 CRITIC/ECP 100 Flash Override 011 Flash 010 Immediate 001 Priority 000 Routine Bit 3 D: 0 = Normal Delay, 1 = Low Delay. Bit 4 T: 0 = Normal Throughput, 1 = High Throughput. Bit 5 R: 0 = Normal Reliability, 1 = High Reliability Bit 6-7: Reserved for Future Use. For this project, the TOS field is used to specify the treatment of an IP packet as it passes through our IP switch. The code points recommended in RFC 2597 Assured Forwarding PHB Group are used. The table below summarizes the recommended AF code point values. These code points do not overlap with any other code points used for general PHB groups. Low Drop Precedence (Green) Medium Drop Precedence (Yellow) Class 1 Class 2 Class 3 Class

16 High Drop Precedence (Red) Process Model The single rate three color marker is implemented in a process model shown in Figure 4. The process model has three states. In the init state, all static variables are initialized. The process model then goes to the idle state. Whenever a new packet is received, the process goes to mark_pk state. The mark_pk state meters and marks the packet according to the srtcm algorithm as explained earlier. This state sends the marked packet to the Decision Processor, and returns to the idle state to wait for the arrival of the next packet. Figure 4 Single Rate Three Color Marker Process Model

17 6 Management Block The Management Block implements the scheduling part of the CMTS. This block has three main functions: controls the number of packets going out of the node, drops packets based on current bandwidth usage and output FIFO size, and maximizes utilization of the outgoing link. The Management Block controls the number of packets going out of the node by utilizing two variables to determine the drop probability of a packet: bandwidth usage of a particular AF Class and the current Output FIFO size. The bandwidth usage of an AF Class determines whether subscribers who belong to a particular AF Class are misbehaving (sending too many packets). If this is the case, the block will look at the current Output FIFO size to determine whether the packets should be dropped or not. Depending on the current bandwidth usage of an AF Class and the current Output FIFO size, the Management Block will drop packets based on the color that is marked on each packet. Packets are dropped based on color so that subscribers who belong to the same AF Class can be differentiated. For instance, packets from a misbehaving subscriber will have a high drop probability compared to a subscriber who is conforming, even though both subscribers are part of the same AF Class. The CMTS needs to maintain a steady outgoing bandwidth to maximize utilization. For this reason, an Output FIFO is used to regulate the number of packets going out at a given time. An optimal maximum Output FIFO size is determined to increase link utilization, at the same time decreasing the latency applied to a packet. There are a total of six different processors that make up the Management Block: Decision Processor, AF Monitor Processor, Multiplexing Processor, Control Processor, Output FIFO, and the Outgoing Monitor Processor. Figure 5 shows a block diagram of the Management Block. Figure 5 Management Block Diagram Decision Processor 1 AF Monitor Processor 1 Decision Processor 2 AF Monitor Processor 2 Decision Processor 3 AF Monitor Processor 3 Multiplexing Processor Outgoing Monitor Processor Decision Processor 4 AF Monitor Processor 4 Packet Queue Control Processor The Management Block uses a Control packet to pass messages between processors. The Control packet format has the following fields: nodeid, and level. The nodeid field tells the receiving processor the source

18 processor that sent the packet. The level field holds either the current bandwidth, FIFO size level, or the dropping level command. 6.1 Decision Processor The Decision Processor decides whether or not to pass packets through the Management Block. There are a total of four Decision Processors used in the Management Block. Each Decision Processor can receive two types of packets: Data packet from an AF Class, or Control packets from the Control Processor. Figure 6 shows the process model used to implement the Decision Processor. Figure 6 Decision Processor Process Model Each Decision Processor has a svcurrentlevel state variable that holds the current dropping level command given by the Control Processor. Table 2 defines the behavior of the Decision Processor on each level. Table 2 Decision Processor Level Definition Level Number Color of packets passed Description 1 Green, Yellow, Red Low bandwidth usage 2 Green, Yellow Medium bandwidth usage 3 Green Maximum bandwidth usage 4 None Bandwidth limit reached The process state determines what type of packet it receives by looking at the packet length. If the packet length is less than 9 bytes, the process state assumes that it has just received a Control packet. If the packet length is greater than or equal to 9 bytes, the process state assumes that is has just received a Data packet from the AF Class.

19 When the process state receives a Control packet, it looks at the level field inside the packet to determine the current dropping level command it should be using. The process state then updates the svcurrentlevel state variable with the new level, and destroys the packet afterwards. When the process state receives a Data packet, it looks at the Type of Service (TOS) field of the packet to determine the color of the packet. The process state then looks at the svcurrentlevel state variable to determine whether the received packet should be dropped or not, as described in Table 2. The appropriate statistical counter is updated when a packet is passed to the next process in the Management Block. When a packet is dropped, a dropped packet statistical counter is incremented to keep track of the number of packets dropped. The packet is dropped by destroying the packet using the op_pk_destroy command. 6.2 AF Monitor Processor There are a total of four AF Monitor Processors in the Management Block, each monitoring the bandwidth usage of an AF Class. Each AF Monitor Processor receives incoming data from a Decision Processor, and transmits the packets to the Multiplexing Processor. Figure 7 shows the process model used to implement the functionality of the AF Monitor Processor. Figure 7 AF Monitor Processor Process Model To monitor the bandwidth usage, an interrupt is generated every second. Ideally, a millisecond timer would provide a more accurate measurement of bandwidth usage, but OPNET is not able to provide such an option in its timer functions.

20 During the init state, a svpacketbytecounter state variable is initialized to 0 and the interrupt timer is started. When a packet is received, the count state reads the packet length parameter using the OPNET command op_pk_total_size_get function. The length of the packet is added to the svpacketbytecounter variable, and the packet is then sent to the Multiplexing Process. When the interrupt timer expires (as indicated by a RESET_CNT event), the timer state reads the current svpacketbytecounter value, and compares this value with the maximum bandwidth value assigned to the AF Class. The AF Monitor Processor determines the appropriate bandwidth usage level for the AF Class and sends the usage level information to the Control Processor. Table 3 shows how the AF Monitor Processor determines the current bandwidth usage level for an AF Class. Table 3 AF Monitor Processor Bandwidth Usage Level Level Number Percent of Maximum Bandwidth Description 1 80% The AF Class is within its expected bandwidth. 2 95% The AF Class is slightly using more bandwidth than what the network administrator has provisioned. 3 95% The AF Class is reaching the maximum limit of the AF class bandwidth % The AF Class has reached its maximum bandwidth. After the timer state determines the appropriate bandwidth usage level, it creates a Control packet and writes its node ID and the bandwidth usage level information. The Control packet is then sent to the Control Processor for further processing. Statistics handles are included in the AF Monitor Process to show the values of important variables (e.g. current bandwidth usage, and total red, yellow, and green packets received). 6.3 Multiplexing Processor The Multiplexing Processor takes in packets coming in from four AF Monitoring Processors, and sends the packets to the Output FIFO. The Multiplexing Processor also keeps track of the current Output FIFO size and updates the Control Processor. There is only one instance of the Multiplexing Processor used in the Management Block. Figure 8 shows the process model used to implement the functionality of the Multiplexing Processor.

21 Figure 8 Multiplexing Processor Process Model The Multiplexing Processor can receive two types of packets: Data packet from the AF Monitor Processors and Update packets from the Outgoing Monitor Processor. Update packets contain the length of the packet that was just transmitted from the Output FIFO. The Multiplexing Processor uses a svcurrentqueuesize state variable to keep track of the current Output FIFO size. When this process sends a packet to the Output FIFO, the svcurrentqueuesize variable is incremented based on the length of the packet that was just transmitted. If the Multiplexing Processor receives an Update packet, the svcurrentqueuesize variable is decremented by the value contained in the Update packet. Every time a Data packet is received, the Multiplexing Processor will update the Control Processor of the current Output FIFO size. For this project, Table 4 lists the different threshold levels used for the Output FIFO size. These threshold values are promoted variables so that they can be set before a simulation is started. Table 4 FIFO Usage Level Level Number FIFO Size (bits) Statistics handles are included in the Multiplexing Processor to show the values of important variables such as the current Output FIFO size, and the number of red, yellow, and green colored packets received.

22 6.4 Control Processor The Control Processor determines how each Decision Processor should behave when receiving incoming packets from the AF Classes. This processor receives updated usage level from the AF Monitor Processors and the Multiplexing Processor to decide what type of dropping level commands to send to each Decision Processor (see Table 2). Figure 9 Control Processor Process Model When a Control packet is received, the decide state examines the nodeid parameter in the packet to determine where the packet came from. A nodeid of 0 3 represents AF Monitor Processors 0-3 respectively. A nodeid of 4 represents the Multiplexing Processor. Once the sender has been identified, the appropriate state variable is updated, and a new dropping level command is sent to each Decision Processor. Table 5 shows the truth table used by the Control Processor to determine the appropriate dropping level command for each Decision Processor. Table 5 Control Process Truth Table AF Monitor Level Output FIFO Size Level

23 The Output FIFO Size Level column represents the current size of the FIFO as reported by the Multiplexing Processor. The AF Monitor Level is the current bandwidth usage of the AF Class as reported by the AF Monitor Processors. The level indicated in the truth table corresponds to the Decision Processor Level Definition as shown in Table 2. Statistics handles are included in the Control Processor to show the values of important variables such as the current FIFO size, current bandwidth level for each AF Class, and the current dropping level command sent to each Decision Process. 6.5 Output FIFO The Output FIFO is used to buffer data in case the incoming packet rate exceeds the outgoing data rate. The Output FIFO is also used to guarantee a constant bandwidth coming out of the CMTS. The acb_fifo model from OPNET was used to implement the functionality of the Output FIFO. The acb_fifo (active, constant, bit) model provided almost all of the functionality that was required. One limitation of the FIFO was that it requires a maximum number of packets and maximum number of bits to be specified. Having to specify both parameters limited the type/number of packets that can be sent to the FIFO without having it overflow. For example, if the maximum number of packets is set to 10 packets and the maximum bit size for the FIFO is set at (corresponding to 576 bytes per packet), the FIFO will overflow if more than 10 packets are transmitted to the output FIFO even if the maximum bits the FIFO can handle has not been reached. When the FIFO overflows, the packet that caused the overflow is simply discarded. The Multiplexing Processor is not notified when a packet is discarded, which causes its FIFO size variable to be inaccurate. 6.6 Outgoing Monitor Processor The Outgoing Monitor Processor has two main functions: send the packet length that was just received from the Output FIFO to the Multiplexing Processor, and monitor the overall bandwidth coming out of the Management Block. As mentioned previously in section 6.3, the Multiplexing Processor uses a svcurrentqueuesize state variable to keep track of the Output FIFO size. The Multiplexing Processor needs to know the packets entering and leaving the Output FIFO to accurately track the current FIFO size. Since it is the only node writing to the Output FIFO, it knows the size of packets entering the Output FIFO. To determine the size of packets exiting the Output FIFO, the Multiplexing Processor needs to receive the packet length information from the Outgoing Monitor Processor. It is important that the Output FIFO does not overflow as neither the Multiplexing Processor nor the Outgoing Monitor Processor will be able to detect this condition. Figure 10 shows the process model used to implement the Output Monitor Processor.

24 Figure 10 Outgoing Monitor Processor Process Model To monitor the bandwidth usage, an interrupt is generated once second. Ideally, a millisecond timer would provide a more accurate measurement of bandwidth usage, but OPNET is not able to provide such an option in its timer functions. During the init state, a svpacketbytecounter state variable is initialized to 0 and the interrupt timer is started. When a packet is received, the count state reads the packet length parameter using the OPNET command op_pk_total_size_get function. The length of the packet is added to the svpacketbytecounter variable, and the packet is then sent to the Subscriber Output Bandwidth Monitor Processor. When the interrupt timer expires (as indicated by a RESET_CNT event), the timer state reads the current svpacketbytecounter value, and updates a Statistics handle to reflect the current bandwidth usage.

25 7 Simulation In order to verify the accuracy of the QoS implementation, there are three main test cases that need to be verified: Test case 1: Within an AF class, if there is traffic congestion, the CMTS should protect the conforming traffic, by dropping misbehaving traffic first. Test case 2: Within an AF class, if there is extra bandwidth, the CMTS should allow more packets to pass through. This allows subscribers to fully utilize the excess bandwidth of the AF Class.. Test case 3: Verify the implementation of the Control Processor scheduling truth table. The diagram below illustrates the top level simulation scenario. The CMTS can support four AF Classes. In the simulation scenario, we have seven customers assigned to 4 AF Classes. Figure 11 Project Model In order to support the testing of the three test cases, the simulation has been configured appropriately by setting the following parameters: Customer packet length and packet inter-arrival rate (more details later) Customer traffic contract CIR, CBS, EBS (more details later) All AF Class Monitor Threshold Level 1 handles bandwidth usage level between 0% and 80% All AF Class Monitor Threshold Level 2 handles bandwidth usage level between 81% and 90% All AF Class Monitor Threshold Level 3 handles bandwidth usage level between 90% and 95%

26 All AF Class Monitor Threshold Level 4 handles bandwidth usage level between 95% and 100%. The simulation ran for 10 minutes. 7.1 AF Class 1 AF Class 1 has the following information: Total Bandwidth: 30 kbps Company A: IP Address: 0 CIR: 20 kbps CBS: 2000 bits EBS: 4608 bits Packet Length: uniform_int(1000 bits, 1900 bits) Inter-arrival time: constant(0.1s) Max Bandwidth: 20 kbps Min Bandwidth: 10 kbps Notes: Company A is a conforming user as its network usage never exceeds the contract. Expect all packets to be marked as green. SOHO A: IP Address: 1 CIR: 10 kbps CBS: 2000 bits EBS: 4608 bits Packet Length: uniform_int(1000 bits, 1900 bits) Inter-arrival time: uniform (0.2 s, 1 s) Max Bandwidth: 10 kbps Min Bandwidth: 1 kbps Notes: SOHO A is a conforming user and all its packets should be marked green. 7.2 AF Class 2 Test case 1 AF Class 2 has the following information: Total Bandwidth: 15 kbps Bank: IP Address: 10 CIR: 10 kbps CBS: 2048 bits EBS: 4608 bits Packet Length: constant(1024 bits) Inter-arrival time: constant(0.125 s) Max Bandwidth: 8 kbps Min Bandwidth: 8 kbps Notes: Bank is a conforming user and it NEVER exceeds the contract. Expect all its packets will be marked as green. SOHO D: IP Address: 11 CIR: 5 kbps

27 CBS: 1024 bits EBS: 4608 bits Packet Length: uniform_int(900 bits, 1100 bits) Inter-arrival time: uniform(0.25 s, 0.3 s) Max Bandwidth: 4.5 kbps Min Bandwidth: 3 kbps Notes: SOHO D is a conforming user most of the time. Expect most of the packets to be marked green, with a few occasional yellow packets. The overall bandwidth usage of AF Class 2 should be around level 1, with an occasional level 2. If the CMTS is implemented correctly, none of the green packets from this class should be dropped and only yellow packets may be dropped. This means that all of the Bank s packets should go through the CMTS. The diagram below shows that the current level of the Decision Processor for AF Class 2 stays at level 1 most of the time. Occasionally, the Decision Processor will go to either level 2 or level 3. When the Decision Processor is at level 2, red packets will be dropped. When the Decision Processor is at level 3, both yellow and red packets will be dropped. Figure 12 Current Level of Decision Process 2 The diagram below shows that there are some green packets and some yellow packets received from AF Class 2.

28 Figure 13 Total Colored Packets for AF Class 2 The diagram below shows that there are some packets that get dropped. Figure 14 Total Dropped Packets for AF Class 2 Bank has an IP address of 10. The diagram below shows that all the Bank s packets are marked green, since it is a conforming user.

29 Figure 15 Bank's Packets In the diagram below, the blue line represents the total number of packets from the Bank coming into the CMTS, and the red line represents the total number of packets from the Bank leaving the CMTS. The diagram show that both incoming and outgoing packet counts are identical; therefore, no packets were dropped.

30 Figure 16 Bank's Incoming and Outgoing Packets Comparison This shows the CMTS behaves as expected and passes test case AF Class 3 Test case 2 AF Class 3 has the following information: Total Bandwidth: 15 kbps SOHO B: IP Address: 20 CIR: 5 kbps CBS: 2048 bits EBS: 4608 bits Packet Length: uniform_int(1500 bits, 2500 bits) Inter-arrival time: uniform (0.4 s, 1 s) Max Bandwidth: 6.3 kbps Min Bandwidth: 1.5 kbps Notes: SOHO B is a misbehaving user so it is expected that there will be some green, yellow, and red colored packets. SOHO C: IP Address: 21 CIR: 5 kbps CBS: 1024 bits EBS: 4608 bits Packet Length: uniform_int(800 bits, 1200 bits) Inter-arrival time: uniform(0.2, 0.3) Max Bandwidth: 6 kbps Min Bandwidth: 2.5 kbps

31 Notes: SOHO C is a misbehaving user so it is expected that there will be some green, yellow, and red colored packets. SOHO B and SOHO C both violate their bandwidth usage contracts by exceeding 5 kbps occasionally. Thus it is expected that some of their packets will be marked as yellow and red. They both belong to AF class 3 with a total allocated bandwidth usage of 15 kbps. The overall bandwidth usage of AF class 3 is approximately less than 75%. This means that the AF Monitor Processor for AF Class 3 should report a Level 1. According the Control Processor schedule truth table (Table 5), if the CMTS is implemented correctly, none of the packets from this class should be dropped, regardless of its color. The diagram below shows that Decision Processor 3 is always at level 1. Figure 17 Current Level of Decision Process 3 In the diagram below, the green curve represents the total number of green packets over time in AF Class 3. The yellow curve represents the total number of yellow packets. The red curve represents the total number of red packets. The diagram shows that there are a lot of green and yellow colored packets, and no red packets.

32 Figure 18 Total Colored Packets in AF Class 3 In the diagram below, the blue curve represents the total number of packets dropped. Since it is zero, it means that no packets were dropped. Figure 19 Total Dropped Packets on AF Class 3

33 This shows the CMTS behaves as expected and passes test case AF Class 4 - Test case 3 AF Class 4 has the following information: Total Bandwidth: 20 kbps Home User: IP Address: 30 CIR: 20 kbps CBS: 2048 bits EBS: 4608 bits Packet Length: uniform_int(1024 bits, 4808 bits) Inter-arrival time: Poisson (0.1) Max Bandwidth: 80 kbps Min Bandwidth: 0 kbps Notes: Home User is a conforming user but sometimes it exceeds CIR and its packet length sometimes exceeds CBS. Expect that there will be green, yellow, and red colored packets.. The dropping level command that a Decision Processor receives depends upon the bandwidth usage of that AF Class and the overall Output FIFO size, as specified in Table 5. In the diagram below, MUX.current Location represents the Output FIFO size level. AFMON4.Level Transmitted represents the bandwidth usage level of AF Class 4. DEC4.Current Level represents the dropping level command given to Decision Processor 4. Figure 20 Current State of AF Class 4 and Multiplexing Process

34 The diagram below is a zoom-in version of the diagram above. Figure 21 Zoomed Diagram of Current State of AF Class 4 and Multiplexing Process At around 2m 14s, the Output FIFO size level is at level 1, and the bandwidth usage level of the AF Class is at level 4. If the Control Processor scheduling truth table (see Table 5) is implemented correctly, the dropping level command given to Decision Processor 4 should be at level 1. This is verified by looking at the DEC4.Current Level graph at time 2m 14s. At around 2 m 17s, the overall Output FIFO size level is at level 2, and the bandwidth usage of AF Class 4 is at level 4. If the Control Processor scheduling truth table (see Table 5) is implemented correctly, the dropping level command given to Decision Processor 4 should be at level 3. This is verified by looking at the DEC4.Current Level graph at time 2m 17s. All other scenarios were tested successfully, but are not discussed in this document. The diagram below shows that there are a lot green, yellow and red marked packets. Furthermore, there are many packets dropped.

35 Figure 22 Total Colored Packets and Total Dropped Packets of AF Class 4 This shows the CMTS behaves as expected and passes test case 3.

36 8 Conclusion The project s goal is to implement a Cable Modem Termination System that will allow service providers to provide different Quality of Services to its customers. In this report, all the blocks, nodes, processes, and test cases were described in detail to show how the entire CMTS work. Based on simulations, the following scenarios were verified: Bandwidth is guaranteed for a conforming subscriber despite being in the same AF Class as a misbehaving subscriber Bandwidth from misbehaving subscribers are not dropped if the total bandwidth coming out of the CMTS is low Only the packets that exceed the subscriber s contract are dropped during congestion Current implementations of CMTS do not provide any bandwidth guarantees to the subscriber. For this reason, it is impossible to reliably use applications that require large bandwidth (e.g. FTP client, online games). Having a QoS based CMTS will allow service providers to charge subscriber more money for guaranteed bandwidth. In this implementation, both the subscribers and the service provider benefit. Subscribers will be satisfied because they can always rely on the bandwidth to be available. The service provider will be satisfied because they can get more revenue from the same existing bandwidth.

37 9 References 1. Jon Postel, Internet Protocol DARPA Internet Program Protocol Specification, RFC791, September K. Nichols, S. Blake, F. Baker, D. Black, Definition of the Differentiated Service Field (DS Field) in the IPv4 and IPv6 Headers, RFC2474, December J. Heinanen, F. Baker, W. Weiss, J. Wroclawski, Assured Forwarding PHB Group, RFC2597, June J. Heinanen, R. Guerin, A Single Rate Three Color Marker, RFC2697, September J. Heinanen, R. Guerin, A Two Rate Three Color Marker, RFC 2698, September Z. Guanqun, Y. Yuan, Fair Bandwidth Allocations through Queue Management in Core-Stateless Networks 7. E. B. Kelly, Quality of Service In Internet Protocol (IP) Networks, Wainhouse Research, Using QoS to Optimize Voice Quality in VoIP Networks, Cisco System,

38 Appendix A: Project Issues Although the project was completed in time, there were some implementation decisions that could have been done differently to make the project more efficient. Statistical Links could have been used extensively to simplify and improve the simulation performance of the CMTS. Instead of statistical links, packet messages were used to send information between processors. From simulation analysis, it has been determined that sending packet messages between two processors did not compromise the results of our implementation. Therefore, it was decided that changing our implementation to statistical link based was not necessary. Another implementation decision that was brought up during the demonstration was the lack of a real-world test case. Searching through the internet did not result in a viable test pattern/test case that can be used as input to the CMTS. Instead, to better emulate a more realistic subscriber traffic behaviour, our simulation time was increased from less than a minute to 10 minutes. All of the results described in the simulation section were based on 10 minute simulation.

Investigation and Comparison of MPLS QoS Solution and Differentiated Services QoS Solutions

Investigation and Comparison of MPLS QoS Solution and Differentiated Services QoS Solutions Investigation and Comparison of MPLS QoS Solution and Differentiated Services QoS Solutions Steve Gennaoui, Jianhua Yin, Samuel Swinton, and * Vasil Hnatyshin Department of Computer Science Rowan University

More information

Quality of Service (QoS) on Netgear switches

Quality of Service (QoS) on Netgear switches Quality of Service (QoS) on Netgear switches Section 1 Principles and Practice of QoS on IP networks Introduction to QoS Why? In a typical modern IT environment, a wide variety of devices are connected

More information

CS/ECE 438: Communication Networks. Internet QoS. Syed Faisal Hasan, PhD (Research Scholar Information Trust Institute) Visiting Lecturer ECE

CS/ECE 438: Communication Networks. Internet QoS. Syed Faisal Hasan, PhD (Research Scholar Information Trust Institute) Visiting Lecturer ECE CS/ECE 438: Communication Networks Internet QoS Syed Faisal Hasan, PhD (Research Scholar Information Trust Institute) Visiting Lecturer ECE Introduction The Internet only provides a best effort service

More information

QoS Parameters. Quality of Service in the Internet. Traffic Shaping: Congestion Control. Keeping the QoS

QoS Parameters. Quality of Service in the Internet. Traffic Shaping: Congestion Control. Keeping the QoS Quality of Service in the Internet Problem today: IP is packet switched, therefore no guarantees on a transmission is given (throughput, transmission delay, ): the Internet transmits data Best Effort But:

More information

Improving Quality of Service

Improving Quality of Service Improving Quality of Service Using Dell PowerConnect 6024/6024F Switches Quality of service (QoS) mechanisms classify and prioritize network traffic to improve throughput. This article explains the basic

More information

Analysis of IP Network for different Quality of Service

Analysis of IP Network for different Quality of Service 2009 International Symposium on Computing, Communication, and Control (ISCCC 2009) Proc.of CSIT vol.1 (2011) (2011) IACSIT Press, Singapore Analysis of IP Network for different Quality of Service Ajith

More information

Smart Queue Scheduling for QoS Spring 2001 Final Report

Smart Queue Scheduling for QoS Spring 2001 Final Report ENSC 833-3: NETWORK PROTOCOLS AND PERFORMANCE CMPT 885-3: SPECIAL TOPICS: HIGH-PERFORMANCE NETWORKS Smart Queue Scheduling for QoS Spring 2001 Final Report By Haijing Fang(hfanga@sfu.ca) & Liu Tang(llt@sfu.ca)

More information

Quality of Service in the Internet. QoS Parameters. Keeping the QoS. Traffic Shaping: Leaky Bucket Algorithm

Quality of Service in the Internet. QoS Parameters. Keeping the QoS. Traffic Shaping: Leaky Bucket Algorithm Quality of Service in the Internet Problem today: IP is packet switched, therefore no guarantees on a transmission is given (throughput, transmission delay, ): the Internet transmits data Best Effort But:

More information

A Preferred Service Architecture for Payload Data Flows. Ray Gilstrap, Thom Stone, Ken Freeman

A Preferred Service Architecture for Payload Data Flows. Ray Gilstrap, Thom Stone, Ken Freeman A Preferred Service Architecture for Payload Data Flows Ray Gilstrap, Thom Stone, Ken Freeman NASA Research and Engineering Network NASA Advanced Supercomputing Division NASA Ames Research Center Outline

More information

02-QOS-ADVANCED-DIFFSRV

02-QOS-ADVANCED-DIFFSRV IP QoS DiffServ Differentiated Services Architecture Agenda DiffServ Principles DS-Field, DSCP Historical Review Newest Implementations Per-Hop Behaviors (PHB) DiffServ in Detail DiffServ in other Environments

More information

Bandwidth Profiles for Ethernet Services Ralph Santitoro

Bandwidth Profiles for Ethernet Services Ralph Santitoro Ralph Santitoro Abstract This paper provides a comprehensive technical overview of bandwidth profiles for Ethernet services, based on the work of the Metro Ethernet Forum (MEF) Technical Committee. The

More information

Quality of Service versus Fairness. Inelastic Applications. QoS Analogy: Surface Mail. How to Provide QoS?

Quality of Service versus Fairness. Inelastic Applications. QoS Analogy: Surface Mail. How to Provide QoS? 18-345: Introduction to Telecommunication Networks Lectures 20: Quality of Service Peter Steenkiste Spring 2015 www.cs.cmu.edu/~prs/nets-ece Overview What is QoS? Queuing discipline and scheduling Traffic

More information

Applications. Network Application Performance Analysis. Laboratory. Objective. Overview

Applications. Network Application Performance Analysis. Laboratory. Objective. Overview Laboratory 12 Applications Network Application Performance Analysis Objective The objective of this lab is to analyze the performance of an Internet application protocol and its relation to the underlying

More information

Internet Quality of Service

Internet Quality of Service Internet Quality of Service Weibin Zhao zwb@cs.columbia.edu 1 Outline 1. Background 2. Basic concepts 3. Supporting mechanisms 4. Frameworks 5. Policy & resource management 6. Conclusion 2 Background:

More information

Modeling and Simulation of Queuing Scheduling Disciplines on Packet Delivery for Next Generation Internet Streaming Applications

Modeling and Simulation of Queuing Scheduling Disciplines on Packet Delivery for Next Generation Internet Streaming Applications Modeling and Simulation of Queuing Scheduling Disciplines on Packet Delivery for Next Generation Internet Streaming Applications Sarhan M. Musa Mahamadou Tembely Matthew N. O. Sadiku Pamela H. Obiomon

More information

Improving QOS in IP Networks. Principles for QOS Guarantees. Principles for QOS Guarantees (more) Principles for QOS Guarantees (more)

Improving QOS in IP Networks. Principles for QOS Guarantees. Principles for QOS Guarantees (more) Principles for QOS Guarantees (more) Improving QOS in IP Networks Thus far: making the best of best effort Future: next generation Internet with QoS guarantees RSVP: signaling for resource reservations Differentiated Services: differential

More information

Figure 1: Network Topology

Figure 1: Network Topology Improving NGN with QoS Strategies Marcel C. Castro, Tatiana B. Pereira, Thiago L. Resende CPqD Telecom & IT Solutions Campinas, S.P., Brazil E-mail: {mcastro; tatibp; tresende}@cpqd.com.br Abstract Voice,

More information

QoS Strategy in DiffServ aware MPLS environment

QoS Strategy in DiffServ aware MPLS environment QoS Strategy in DiffServ aware MPLS environment Teerapat Sanguankotchakorn, D.Eng. Telecommunications Program, School of Advanced Technologies Asian Institute of Technology P.O.Box 4, Klong Luang, Pathumthani,

More information

Bandwidth Profiles for Ethernet Services Ralph Santitoro

Bandwidth Profiles for Ethernet Services Ralph Santitoro Ralph Santitoro Abstract This paper provides a comprehensive technical overview of bandwidth profiles for Ethernet services, based on the work (as of October 2003) of the Metro Ethernet Forum (MEF) Technical

More information

18: Enhanced Quality of Service

18: Enhanced Quality of Service 18: Enhanced Quality of Service Mark Handley Traditional best-effort queuing behaviour in routers Data transfer: datagrams: individual packets no recognition of flows connectionless: no signalling Forwarding:

More information

Requirements of Voice in an IP Internetwork

Requirements of Voice in an IP Internetwork Requirements of Voice in an IP Internetwork Real-Time Voice in a Best-Effort IP Internetwork This topic lists problems associated with implementation of real-time voice traffic in a best-effort IP internetwork.

More information

Burst Testing. New mobility standards and cloud-computing network. This application note will describe how TCP creates bursty

Burst Testing. New mobility standards and cloud-computing network. This application note will describe how TCP creates bursty Burst Testing Emerging high-speed protocols in mobility and access networks, combined with qualityof-service demands from business customers for services such as cloud computing, place increased performance

More information

This topic lists the key mechanisms use to implement QoS in an IP network.

This topic lists the key mechanisms use to implement QoS in an IP network. IP QoS Mechanisms QoS Mechanisms This topic lists the key mechanisms use to implement QoS in an IP network. QoS Mechanisms Classification: Each class-oriented QoS mechanism has to support some type of

More information

Differentiated Services

Differentiated Services March 19, 1998 Gordon Chaffee Berkeley Multimedia Research Center University of California, Berkeley Email: chaffee@bmrc.berkeley.edu URL: http://bmrc.berkeley.edu/people/chaffee 1 Outline Architecture

More information

Chapter 7 outline. 7.5 providing multiple classes of service 7.6 providing QoS guarantees RTP, RTCP, SIP. 7: Multimedia Networking 7-71

Chapter 7 outline. 7.5 providing multiple classes of service 7.6 providing QoS guarantees RTP, RTCP, SIP. 7: Multimedia Networking 7-71 Chapter 7 outline 7.1 multimedia networking applications 7.2 streaming stored audio and video 7.3 making the best out of best effort service 7.4 protocols for real-time interactive applications RTP, RTCP,

More information

Faculty of Engineering Computer Engineering Department Islamic University of Gaza 2012. Network Chapter# 19 INTERNETWORK OPERATION

Faculty of Engineering Computer Engineering Department Islamic University of Gaza 2012. Network Chapter# 19 INTERNETWORK OPERATION Faculty of Engineering Computer Engineering Department Islamic University of Gaza 2012 Network Chapter# 19 INTERNETWORK OPERATION Review Questions ٢ Network Chapter# 19 INTERNETWORK OPERATION 19.1 List

More information

6.6 Scheduling and Policing Mechanisms

6.6 Scheduling and Policing Mechanisms 02-068 C06 pp4 6/14/02 3:11 PM Page 572 572 CHAPTER 6 Multimedia Networking 6.6 Scheduling and Policing Mechanisms In the previous section, we identified the important underlying principles in providing

More information

Quality of Service Analysis of site to site for IPSec VPNs for realtime multimedia traffic.

Quality of Service Analysis of site to site for IPSec VPNs for realtime multimedia traffic. Quality of Service Analysis of site to site for IPSec VPNs for realtime multimedia traffic. A Network and Data Link Layer infrastructure Design to Improve QoS in Voice and video Traffic Jesús Arturo Pérez,

More information

Sources: Chapter 6 from. Computer Networking: A Top-Down Approach Featuring the Internet, by Kurose and Ross

Sources: Chapter 6 from. Computer Networking: A Top-Down Approach Featuring the Internet, by Kurose and Ross M ultimedia Communication Multimedia Systems(Module 5 Lesson 3) Summary: Beyond Best-Effort Motivating QoS Q uality of Service (QoS) Scheduling and Policing Sources: Chapter 6 from Computer Networking:

More information

Module 7 Internet And Internet Protocol Suite

Module 7 Internet And Internet Protocol Suite Module 7 Internet And Internet Protocol Suite Lesson 21 Internet and IPv4 LESSON OBJECTIVE General The lesson will discuss a popular network layer protocol, i.e. the Internet Protocol Specific The focus

More information

Network Simulation Traffic, Paths and Impairment

Network Simulation Traffic, Paths and Impairment Network Simulation Traffic, Paths and Impairment Summary Network simulation software and hardware appliances can emulate networks and network hardware. Wide Area Network (WAN) emulation, by simulating

More information

King Fahd University of Petroleum & Minerals Computer Engineering g Dept

King Fahd University of Petroleum & Minerals Computer Engineering g Dept King Fahd University of Petroleum & Minerals Computer Engineering g Dept COE 543 Mobile and Wireless Networks Term 111 Dr. Ashraf S. Hasan Mahmoud Rm 22-148-3 Ext. 1724 Email: ashraf@kfupm.edu.sa 12/24/2011

More information

APPLICATION NOTE 209 QUALITY OF SERVICE: KEY CONCEPTS AND TESTING NEEDS. Quality of Service Drivers. Why Test Quality of Service?

APPLICATION NOTE 209 QUALITY OF SERVICE: KEY CONCEPTS AND TESTING NEEDS. Quality of Service Drivers. Why Test Quality of Service? QUALITY OF SERVICE: KEY CONCEPTS AND TESTING NEEDS By Thierno Diallo, Product Specialist With the increasing demand for advanced voice and video services, the traditional best-effort delivery model is

More information

A Review on Quality of Service Architectures for Internet Network Service Provider (INSP)

A Review on Quality of Service Architectures for Internet Network Service Provider (INSP) A Review on Quality of Service Architectures for Internet Network Service Provider (INSP) Herman and Azizah bte Abd. Rahman Faculty of Computer Science and Information System Universiti Teknologi Malaysia

More information

Multimedia Requirements. Multimedia and Networks. Quality of Service

Multimedia Requirements. Multimedia and Networks. Quality of Service Multimedia Requirements Chapter 2: Representation of Multimedia Data Chapter 3: Multimedia Systems Communication Aspects and Services Multimedia Applications and Transfer/Control Protocols Quality of Service

More information

ENSC 427: COMMUNICATION NETWORKS ANALYSIS ON VOIP USING OPNET

ENSC 427: COMMUNICATION NETWORKS ANALYSIS ON VOIP USING OPNET ENSC 427: COMMUNICATION NETWORKS ANALYSIS ON VOIP USING OPNET FINAL PROJECT Benson Lam 301005441 btl2@sfu.ca Winfield Zhao 200138485 wzhao@sfu.ca Mincong Luo 301039612 mla22@sfu.ca Data: April 05, 2009

More information

Introduction to Differentiated Services (DiffServ) and HP-UX IPQoS

Introduction to Differentiated Services (DiffServ) and HP-UX IPQoS Introduction to Differentiated Services (DiffServ) and HP-UX IPQoS What is Quality of Service (QoS)?... 2 Differentiated Services (DiffServ)... 2 Overview... 2 Example XYZ Corporation... 2 Components of

More information

EXPERIMENTAL STUDY FOR QUALITY OF SERVICE IN VOICE OVER IP

EXPERIMENTAL STUDY FOR QUALITY OF SERVICE IN VOICE OVER IP Scientific Bulletin of the Electrical Engineering Faculty Year 11 No. 2 (16) ISSN 1843-6188 EXPERIMENTAL STUDY FOR QUALITY OF SERVICE IN VOICE OVER IP Emil DIACONU 1, Gabriel PREDUŞCĂ 2, Denisa CÎRCIUMĂRESCU

More information

Quality of Service (QoS)) in IP networks

Quality of Service (QoS)) in IP networks Quality of Service (QoS)) in IP networks Petr Grygárek rek 1 Quality of Service (QoS( QoS) QoS is the ability of network to support applications without limiting it s s function or performance ITU-T T

More information

Performance Evaluation of the Impact of QoS Mechanisms in an IPv6 Network for IPv6-Capable Real-Time Applications

Performance Evaluation of the Impact of QoS Mechanisms in an IPv6 Network for IPv6-Capable Real-Time Applications Journal of Network and Systems Management, Vol. 12, No. 4, December 2004 ( C 2004) DOI: 10.1007/s10922-004-0672-5 Performance Evaluation of the Impact of QoS Mechanisms in an IPv6 Network for IPv6-Capable

More information

CHAPTER 2. QoS ROUTING AND ITS ROLE IN QOS PARADIGM

CHAPTER 2. QoS ROUTING AND ITS ROLE IN QOS PARADIGM CHAPTER 2 QoS ROUTING AND ITS ROLE IN QOS PARADIGM 22 QoS ROUTING AND ITS ROLE IN QOS PARADIGM 2.1 INTRODUCTION As the main emphasis of the present research work is on achieving QoS in routing, hence this

More information

Effects of Filler Traffic In IP Networks. Adam Feldman April 5, 2001 Master s Project

Effects of Filler Traffic In IP Networks. Adam Feldman April 5, 2001 Master s Project Effects of Filler Traffic In IP Networks Adam Feldman April 5, 2001 Master s Project Abstract On the Internet, there is a well-documented requirement that much more bandwidth be available than is used

More information

QoS: Color-Aware Policer

QoS: Color-Aware Policer QoS: Color-Aware Policer First Published: August 26, 2003 Last Updated: February 28, 2006 The QoS: Color-Aware Policer enables a color-aware method of traffic policing. This feature allows you to police

More information

Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services

Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services 1 Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services Arjan Durresi 1, Sastri Kota 2, Mukul Goyal 1, Raj Jain 3, Venkata Bharani 1 1 Department of Computer and Information

More information

Frame Metering in 802.1Q Version 01

Frame Metering in 802.1Q Version 01 Frame Metering in 802.1Q Version 01 Stephen Haddock January 15, 2013 1 Overview Frame metering introduced in 802.1ad-2005 in conjunction with the DEI bit of the S-VLAN tag. The DEI bit was introduced to

More information

The Impact of QoS Changes towards Network Performance

The Impact of QoS Changes towards Network Performance International Journal of Computer Networks and Communications Security VOL. 3, NO. 2, FEBRUARY 2015, 48 53 Available online at: www.ijcncs.org E-ISSN 2308-9830 (Online) / ISSN 2410-0595 (Print) The Impact

More information

Distributed Systems 3. Network Quality of Service (QoS)

Distributed Systems 3. Network Quality of Service (QoS) Distributed Systems 3. Network Quality of Service (QoS) Paul Krzyzanowski pxk@cs.rutgers.edu 1 What factors matter for network performance? Bandwidth (bit rate) Average number of bits per second through

More information

SIP Trunking and Voice over IP

SIP Trunking and Voice over IP SIP Trunking and Voice over IP Agenda What is SIP Trunking? SIP Signaling How is Voice encoded and transported? What are the Voice over IP Impairments? How is Voice Quality measured? VoIP Technology Confidential

More information

AlliedWare Plus TM OS How To. Configure QoS to Conform to Standard Marking Schemes. Introduction. Contents

AlliedWare Plus TM OS How To. Configure QoS to Conform to Standard Marking Schemes. Introduction. Contents AlliedWare Plus TM OS How To Configure QoS to Conform to Standard Marking Schemes Introduction This How To Note describes how to deploy a QoS solution across an entire network. It explains how to define

More information

The network we see so far. Internet Best Effort Service. Is best-effort good enough? An Audio Example. Network Support for Playback

The network we see so far. Internet Best Effort Service. Is best-effort good enough? An Audio Example. Network Support for Playback The network we see so far CSE56 - Lecture 08 QoS Network Xiaowei Yang TCP saw-tooth FIFO w/ droptail or red Best-effort service Web-surfing, email, ftp, file-sharing Internet Best Effort Service Our network

More information

Quality of Service. Traditional Nonconverged Network. Traditional data traffic characteristics:

Quality of Service. Traditional Nonconverged Network. Traditional data traffic characteristics: Quality of Service 1 Traditional Nonconverged Network Traditional data traffic characteristics: Bursty data flow FIFO access Not overly time-sensitive; delays OK Brief outages are survivable 2 1 Converged

More information

COMPARATIVE ANALYSIS OF DIFFERENT QUEUING MECHANISMS IN HETROGENEOUS NETWORKS

COMPARATIVE ANALYSIS OF DIFFERENT QUEUING MECHANISMS IN HETROGENEOUS NETWORKS COMPARATIVE ANALYSIS OF DIFFERENT QUEUING MECHANISMS IN HETROGENEOUS NETWORKS Shubhangi Rastogi 1, Samir Srivastava 2 M.Tech Student, Computer Science and Engineering, KNIT, Sultanpur, India 1 Associate

More information

4 Internet QoS Management

4 Internet QoS Management 4 Internet QoS Management Rolf Stadler School of Electrical Engineering KTH Royal Institute of Technology stadler@ee.kth.se September 2008 Overview Network Management Performance Mgt QoS Mgt Resource Control

More information

Access the Test Here http://myspeed.visualware.com/index.php

Access the Test Here http://myspeed.visualware.com/index.php VoIP Speed Test Why run the test? Running a VoIP speed test is an effective way to gauge whether your Internet connection is suitable to run a hosted telephone system using VoIP technology. A number of

More information

QoS in Axis Video Products

QoS in Axis Video Products Table of contents 1 Quality of Service...3 1.1 What is QoS?...3 1.2 Requirements for QoS...3 1.3 A QoS network scenario...3 2 QoS models...4 2.1 The IntServ model...4 2.2 The DiffServ model...5 2.3 The

More information

Enhanced Content Delivery Network to Improve the QoE

Enhanced Content Delivery Network to Improve the QoE Enhanced Content Delivery Network to Improve the QoE 1 Sachendra Singh Solanky, 2 Sandra Brigit Johnson, 3 Vakkalagadda Eswar Praphul 1 M.Tech Student SCSE, VIT University Chennai-600048, 2 M.Tech Student

More information

Network Management Quality of Service I

Network Management Quality of Service I Network Management Quality of Service I Patrick J. Stockreisser p.j.stockreisser@cs.cardiff.ac.uk Lecture Outline Basic Network Management (Recap) Introduction to QoS Packet Switched Networks (Recap) Common

More information

Mixer/Translator VOIP/SIP. Translator. Mixer

Mixer/Translator VOIP/SIP. Translator. Mixer Mixer/Translator VOIP/SIP RTP Mixer, translator A mixer combines several media stream into a one new stream (with possible new encoding) reduced bandwidth networks (video or telephone conference) appears

More information

Three Key Design Considerations of IP Video Surveillance Systems

Three Key Design Considerations of IP Video Surveillance Systems Three Key Design Considerations of IP Video Surveillance Systems 2012 Moxa Inc. All rights reserved. Three Key Design Considerations of IP Video Surveillance Systems Copyright Notice 2012 Moxa Inc. All

More information

CHAPTER 4 ACTIVE QUEUE MANAGEMENT

CHAPTER 4 ACTIVE QUEUE MANAGEMENT 74 CHAPTER 4 ACTIVE QUEUE MANAGEMENT 4.1 INTRODUCTION QoS in the existing and emerging applications in the Internet has been a big challenge to the Internet Programmer. Real time applications such as audio/video

More information

Real-time apps and Quality of Service

Real-time apps and Quality of Service Real-time apps and Quality of Service Focus What transports do applications need? What network mechanisms provide which kinds of quality assurances? Topics Real-time versus Elastic applications Adapting

More information

Quality of Service (QoS): Managing Bandwidth More Effectively on the Series 2600/2600-PWR and Series 2800 Switches

Quality of Service (QoS): Managing Bandwidth More Effectively on the Series 2600/2600-PWR and Series 2800 Switches 6 Quality of Service (QoS): Managing Bandwidth More Effectively on the Series 2600/2600-PWR and Series 2800 Switches Contents Introduction................................................... 6-3 Terminology................................................

More information

Per-Flow Queuing Allot's Approach to Bandwidth Management

Per-Flow Queuing Allot's Approach to Bandwidth Management White Paper Per-Flow Queuing Allot's Approach to Bandwidth Management Allot Communications, July 2006. All Rights Reserved. Table of Contents Executive Overview... 3 Understanding TCP/IP... 4 What is Bandwidth

More information

The Affects of Different Queuing Algorithms within the Router on QoS VoIP application Using OPNET

The Affects of Different Queuing Algorithms within the Router on QoS VoIP application Using OPNET The Affects of Different Queuing Algorithms within the Router on QoS VoIP application Using OPNET Abstract: Dr. Hussein A. Mohammed*, Dr. Adnan Hussein Ali**, Hawraa Jassim Mohammed* * Iraqi Commission

More information

Can PowerConnect Switches Be Used in VoIP Deployments?

Can PowerConnect Switches Be Used in VoIP Deployments? PowerConnect Application Note #11 February 2004 Can PowerConnect Switches Be Used in VoIP Deployments? This Application Notes relates to the following Dell PowerConnect products: PowerConnect 33xx PowerConnect

More information

iseries Quality of service

iseries Quality of service iseries Quality of service iseries Quality of service Copyright International Business Machines Corporation 2001. All rights reserved. US Government Users Restricted Rights Use, duplication or disclosure

More information

Voice Over IP Performance Assurance

Voice Over IP Performance Assurance Voice Over IP Performance Assurance Transforming the WAN into a voice-friendly using Exinda WAN OP 2.0 Integrated Performance Assurance Platform Document version 2.0 Voice over IP Performance Assurance

More information

Transport Layer Protocols

Transport Layer Protocols Transport Layer Protocols Version. Transport layer performs two main tasks for the application layer by using the network layer. It provides end to end communication between two applications, and implements

More information

Basic Multiplexing models. Computer Networks - Vassilis Tsaoussidis

Basic Multiplexing models. Computer Networks - Vassilis Tsaoussidis Basic Multiplexing models? Supermarket?? Computer Networks - Vassilis Tsaoussidis Schedule Where does statistical multiplexing differ from TDM and FDM Why are buffers necessary - what is their tradeoff,

More information

DOCSIS 1.1 Cable Modem Termination Systems

DOCSIS 1.1 Cable Modem Termination Systems DOCSIS 1.1 Cable Modem Termination Systems Chris Bridge cbridge@motorola.com DOCSIS 1.1 Features QoS management Dynamic QoS management Dynamic QoS addition Dynamic QoS change Dynamic QoS deletion Policy-based

More information

Performance Evaluation of VoIP Services using Different CODECs over a UMTS Network

Performance Evaluation of VoIP Services using Different CODECs over a UMTS Network Performance Evaluation of VoIP Services using Different CODECs over a UMTS Network Jianguo Cao School of Electrical and Computer Engineering RMIT University Melbourne, VIC 3000 Australia Email: j.cao@student.rmit.edu.au

More information

About Firewall Protection

About Firewall Protection 1. This guide describes how to configure basic firewall rules in the UTM to protect your network. The firewall then can provide secure, encrypted communications between your local network and a remote

More information

Quality of Service for IP Videoconferencing Engineering White Paper

Quality of Service for IP Videoconferencing Engineering White Paper Engineering White Paper Subha Dhesikan Cisco Systems June 1 st, 2001 Copyright 2002 Cisco Systems, Inc. Table of Contents 1 INTRODUCTION 4 2 WHY QOS? 4 3 QOS PRIMITIVES 5 4 QOS ARCHITECTURES 7 4.1 DIFFERENTIATED

More information

VoIP QoS on low speed links

VoIP QoS on low speed links Ivana Pezelj Croatian Academic and Research Network - CARNet J. Marohni a bb 0 Zagreb, Croatia Ivana.Pezelj@CARNet.hr QoS on low speed links Julije Ožegovi Faculty of Electrical Engineering, Mechanical

More information

3. MONITORING AND TESTING THE ETHERNET NETWORK

3. MONITORING AND TESTING THE ETHERNET NETWORK 3. MONITORING AND TESTING THE ETHERNET NETWORK 3.1 Introduction The following parameters are covered by the Ethernet performance metrics: Latency (delay) the amount of time required for a frame to travel

More information

1. The subnet must prevent additional packets from entering the congested region until those already present can be processed.

1. The subnet must prevent additional packets from entering the congested region until those already present can be processed. Congestion Control When one part of the subnet (e.g. one or more routers in an area) becomes overloaded, congestion results. Because routers are receiving packets faster than they can forward them, one

More information

1.1. Abstract. 1.2. VPN Overview

1.1. Abstract. 1.2. VPN Overview 1.1. Abstract Traditionally organizations have designed their VPN networks using layer 2 WANs that provide emulated leased lines. In the last years a great variety of VPN technologies has appeared, making

More information

VoIP network planning guide

VoIP network planning guide VoIP network planning guide Document Reference: Volker Schüppel 08.12.2009 1 CONTENT 1 CONTENT... 2 2 SCOPE... 3 3 BANDWIDTH... 4 3.1 Control data 4 3.2 Audio codec 5 3.3 Packet size and protocol overhead

More information

CS640: Introduction to Computer Networks. Why a New Service Model? Utility curve Elastic traffic. Aditya Akella. Lecture 20 QoS

CS640: Introduction to Computer Networks. Why a New Service Model? Utility curve Elastic traffic. Aditya Akella. Lecture 20 QoS CS640: Introduction to Computer Networks Aditya Akella Lecture 20 QoS Why a New Service Model? Best effort clearly insufficient Some applications need more assurances from the network What is the basic

More information

A NOVEL RESOURCE EFFICIENT DMMS APPROACH

A NOVEL RESOURCE EFFICIENT DMMS APPROACH A NOVEL RESOURCE EFFICIENT DMMS APPROACH FOR NETWORK MONITORING AND CONTROLLING FUNCTIONS Golam R. Khan 1, Sharmistha Khan 2, Dhadesugoor R. Vaman 3, and Suxia Cui 4 Department of Electrical and Computer

More information

What VoIP Requires From a Data Network

What VoIP Requires From a Data Network A White Paper by NEC Unified Solutions, Inc. What VoIP Requires From a Data Network Introduction Here is a very common story. A customer has a data network based on TCP/IP that is working well. He can

More information

Quality of Service (QoS) for Enterprise Networks. Learn How to Configure QoS on Cisco Routers. Share:

Quality of Service (QoS) for Enterprise Networks. Learn How to Configure QoS on Cisco Routers. Share: Quality of Service (QoS) for Enterprise Networks Learn How to Configure QoS on Cisco Routers Share: Quality of Service (QoS) Overview Networks today are required to deliver secure, measurable and guaranteed

More information

Chapter 4. VoIP Metric based Traffic Engineering to Support the Service Quality over the Internet (Inter-domain IP network)

Chapter 4. VoIP Metric based Traffic Engineering to Support the Service Quality over the Internet (Inter-domain IP network) Chapter 4 VoIP Metric based Traffic Engineering to Support the Service Quality over the Internet (Inter-domain IP network) 4.1 Introduction Traffic Engineering can be defined as a task of mapping traffic

More information

Technology Overview. Class of Service Overview. Published: 2014-01-10. Copyright 2014, Juniper Networks, Inc.

Technology Overview. Class of Service Overview. Published: 2014-01-10. Copyright 2014, Juniper Networks, Inc. Technology Overview Class of Service Overview Published: 2014-01-10 Juniper Networks, Inc. 1194 North Mathilda Avenue Sunnyvale, California 94089 USA 408-745-2000 www.juniper.net Juniper Networks, Junos,

More information

Broadband 101: Installation and Testing

Broadband 101: Installation and Testing Broadband 101: Installation and Testing Fanny Mlinarsky Introduction Today the Internet is an information superhighway with bottlenecks at every exit. These congested exits call for the deployment of broadband

More information

Chapter 4 Rate Limiting

Chapter 4 Rate Limiting Chapter 4 Rate Limiting HP s rate limiting enables you to control the amount of bandwidth specific Ethernet traffic uses on specific interfaces, by limiting the amount of data the interface receives or

More information

Network-based Quality of Service for Polycom IP Videoconferencing

Network-based Quality of Service for Polycom IP Videoconferencing Network-based Quality of Service Date: June 2005 Copyright 2005: Pinacl Solutions UK Ltd INTRODUCTION... 3 INFORMATION SOURCES...3 NETWORK-BASED QUALITY OF SERVICE (NQOS) SERVICE LEVELS... 3 Best eft service...3

More information

The Conversion Technology Experts. Quality of Service (QoS) in High-Priority Applications

The Conversion Technology Experts. Quality of Service (QoS) in High-Priority Applications The Conversion Technology Experts Quality of Service (QoS) in High-Priority Applications Abstract It is apparent that with the introduction of new technologies such as Voice over IP and digital video,

More information

QoS Tools in the WAN. Need for QoS on WAN Links. Need for QoS in the WAN

QoS Tools in the WAN. Need for QoS on WAN Links. Need for QoS in the WAN QoS Tools in the WAN Need for QoS on WAN Links This topic defines the need for QoS in a WAN. Need for QoS in the WAN Voice must compete with data. Voice is real-time and must be sent first. Overhead should

More information

ENSC 427- Communication Networks Spring 2015. Quality of service of the wireless networking standard over a Multi user environment.

ENSC 427- Communication Networks Spring 2015. Quality of service of the wireless networking standard over a Multi user environment. ENSC 427- Communication Networks Spring 2015 Quality of service of the wireless networking standard over a Multi user environment Group 9 Name: Saumya Sangal Email: ssangal@sfu.ca Name: Jasmine Liu Email:

More information

Networkbased. Quality of Service. Communicate Simply. For IP Video Conferencing

Networkbased. Quality of Service. Communicate Simply. For IP Video Conferencing Communicate Simply Networkbased Quality of Service For IP Video Conferencing Timothy M. O Neil Director of Technical Marketing Polycom Video Communications Table of Contents Introduction...1 Information

More information

AN OVERVIEW OF QUALITY OF SERVICE COMPUTER NETWORK

AN OVERVIEW OF QUALITY OF SERVICE COMPUTER NETWORK Abstract AN OVERVIEW OF QUALITY OF SERVICE COMPUTER NETWORK Mrs. Amandeep Kaur, Assistant Professor, Department of Computer Application, Apeejay Institute of Management, Ramamandi, Jalandhar-144001, Punjab,

More information

Application Note Telephony Service over Satellite

Application Note Telephony Service over Satellite Voice over Application Note Telephony Service over Satellite January 2012 Data Sells but Voice Pays In the early years of the industry, networks were deployed primarily for telephony services. As time

More information

CHAPTER 1 ATM TRAFFIC MANAGEMENT

CHAPTER 1 ATM TRAFFIC MANAGEMENT CHAPTER 1 ATM TRAFFIC MANAGEMENT Webster s New World Dictionary defines congestion as filled to excess, or overcrowded; for example, highway congestion. Although, the best solution of congestion is to

More information

Overview of QoS in Packet-based IP and MPLS Networks. Paresh Shah Utpal Mukhopadhyaya Arun Sathiamurthi

Overview of QoS in Packet-based IP and MPLS Networks. Paresh Shah Utpal Mukhopadhyaya Arun Sathiamurthi Overview of QoS in Packet-based IP and MPLS Networks Paresh Shah Utpal Mukhopadhyaya Arun Sathiamurthi 1 Agenda Introduction QoS Service Models DiffServ QoS Techniques MPLS QoS Summary 2 Introduction QoS

More information

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK

ESSENTIALS. Understanding Ethernet Switches and Routers. April 2011 VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK VOLUME 3 ISSUE 1 A TECHNICAL SUPPLEMENT TO CONTROL NETWORK Contemporary Control Systems, Inc. Understanding Ethernet Switches and Routers This extended article was based on a two-part article that was

More information

PERFORMANCE ANALYSIS OF VOIP TRAFFIC OVER INTEGRATING WIRELESS LAN AND WAN USING DIFFERENT CODECS

PERFORMANCE ANALYSIS OF VOIP TRAFFIC OVER INTEGRATING WIRELESS LAN AND WAN USING DIFFERENT CODECS PERFORMANCE ANALYSIS OF VOIP TRAFFIC OVER INTEGRATING WIRELESS LAN AND WAN USING DIFFERENT CODECS Ali M. Alsahlany 1 1 Department of Communication Engineering, Al-Najaf Technical College, Foundation of

More information

VoIP Performance Over different service Classes Under Various Scheduling Techniques

VoIP Performance Over different service Classes Under Various Scheduling Techniques Australian Journal of Basic and Applied Sciences, 5(11): 1416-1422-CC, 211 ISSN 1991-8178 VoIP Performance Over different service Classes Under Various Scheduling Techniques Ahmad Karim Bahauddin Zakariya

More information

WhitePaper: XipLink Real-Time Optimizations

WhitePaper: XipLink Real-Time Optimizations WhitePaper: XipLink Real-Time Optimizations XipLink Real Time Optimizations Header Compression, Packet Coalescing and Packet Prioritization Overview XipLink Real Time ( XRT ) is a new optimization capability

More information

COMMUNITY COMMUNICATIONS COMPANY (CCC CABLE) BROADBAND INTERNET SERVICE DISCLOSURES

COMMUNITY COMMUNICATIONS COMPANY (CCC CABLE) BROADBAND INTERNET SERVICE DISCLOSURES COMMUNITY COMMUNICATIONS COMPANY (CCC CABLE) BROADBAND INTERNET SERVICE DISCLOSURES Update April 1, 2015 Consistent with FCC regulations,[1] CCC CABLE provides this information about our broadband Internet

More information