THE BCS PROFESSIONAL EXAMINATIONS BCS Level 5 Diploma in IT. October 2009 EXAMINERS' REPORT. Computer Networks

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "THE BCS PROFESSIONAL EXAMINATIONS BCS Level 5 Diploma in IT. October 2009 EXAMINERS' REPORT. Computer Networks"

Transcription

1 THE BCS PROFESSIONAL EXAMINATIONS BCS Level 5 Diploma in IT October 2009 EXAMINERS' REPORT Computer Networks General Comments The responses to questions were of marginally better quality than April 2009 examinations, although some of them were of varying quality. Again a number of students were on the borderline or near borderline pass category, the latter forming a group not as large as in April 2009 examination. The number of passes was higher than the previous examination and there were more good answers in this session. There were a number of students who were extremely articulate and descriptive in their understanding, unfortunately many of these students fail to apply their knowledge in demonstrated understanding by answering the question in front of them. This has been a significant factor worth noting as it is obvious that student have been cued in the questions to reproduce an answer without actually reviewing the question closely. That said there were some really excellent informed and clearly very engaged networking student prepared to illustrate conceptual answer and backing them up with practical real world network knowledge. In general, students need better preparation based on good understanding of concepts which alone ensures good performance. The students are strongly advised to read examiners reports such as this as part of their preparation for the examination besides preparing answers for questions.. Section A A1 a. A commonly used network access technology for providing Internet access to the home is Asymmetric Digital Subscriber Line (ADSL). Explain what is meant by the term asymmetric and why it is particularly suited to accessing the world wide web? (4 marks) b. The ADSL technology uses the same wires that connect a home to the Plain Old Telephone Service (POTS). Draw a typical ADSL architecture that connects a home to the Internet via the local POTS exchange and describe the function provided by the ADSL router, micro-filter and Digital Subscriber Line Access Multiplexer (DSLAM). c. Briefly describe the Discrete Multi-tone (DMT) modulation scheme used by ADSL and identify those factors which determine how much bandwidth a given customer will receive within their home. (11 marks) 1

2 Answer pointers a) Asymmetric means that the upstream bandwidth is different to the downstream bandwidth. When accessing the world wide web, the bandwidth required from the user to the web is generally always much lower than the other way around. Typically, a url (low volume data) is issued to the web which will result in the delivery of a large file (the website). 2 marks for asymmetric being unbalanced in up and downstream. 2 marks for recognising that normal web access is also unbalanced, i.e. asymmetric. b) The ADSL technology uses the same wires that connect a home to the Plain Old Telephone Service (POTS). Draw a typical ADSL architecture that connects a home to the Internet via the local POTS exchange and describe the function provided by the ADSL router, micro-filter and Digital Subscriber Line Access Multiplexer (DSLAM). ADSL Router The ADSL router provides an interface for locally attached computers, typically using a WiFi or Ethernet port connection. Micro-filter The micro-filter separates in frequency, the analogue telephone (POTS) from the data stream generated by the ADSL router. DSLAM The DSLAM is within the local exchange and this accepts the data from the telephone lines and provides an interface and access to the Internet service. 4 marks for diagram, 2 marks each for a description of the ADSL Router, Micro-filter and DSLAM Conventional analogue telephony uses frequencies up to 4kHz. ADSL digital signals occupy 26 khz to 1.1MHz. This bandwidth is then divided into 256 channels, each of 4.3kHz. Within these 256 channels, adaptive coding is used (QPSK, QAM) to encode up to 64 kbps per channel. The factors that determine the delivered bandwidth are: The quality of the wire connecting the home to the local exchange The distance from the local exchange (both of the above affect signal attenuation and quality which means that less data can be encoded into each frequency channel.) The contention ratio of the DSLAM will also affect performance in that as more users try and access the Internet so each will get proportionately less bandwidth. DMT: 2 marks for separation of telephony and data, 2 marks for division of frequency into channels, 2 marks for adaptive modulation per channel. Factors: 2 marks for quality and length of wire to exchange, 2 marks for signal degradation and 1 mark for contention ratio of DSLAM. 2

3 Examiners Comments: This the most troublesome on the paper, attempted by the least number of students and with the lowest performance. Most common mistake was to discuss synchronous and asynchronous networks. Weaker students were less sure of DSLAM function and they tended to have the appearance of experience of end user view of ADSL rather than a taught understanding. Several students gave valiant descriptions of DMT (unfortunately at the expense of the later part of performance) but clearly the majority of the students don t have this knowledge or feel that getting into detail mattered. A2 a. Explain what is meant by the term virtual circuit. (4 marks) b. In networks such as Frame Relay and ATM, virtual circuits are established in accordance with a traffic contract. What is a traffic contract and briefly describe what it defines. (6 marks) c. Explain the process by which a virtual circuit is established using TCP. (11 marks) d. What function is provided by TCP port numbers and what is meant by the term well known port? (4 marks) Answer pointers a) A virtual circuit is the means by which devices establish a communications link between themselves within a packet or cell switched network. Once established a virtual circuit appears as a dedicated and separate link between two points. 2 marks for a VP being a connection, 1 mark for it operating over a packet switched network and 1 mark for it appearing as a dedicated link. b) A traffic contract defines the Quality of Service (QoS) required over a particular virtual circuit connection. The contract therefore needs to define the traffic profile to be supported together with details of its timing requirements. Typical parameters would include average data rate, peak rate, maximum and maximum rates, end to end delay and delay variance requirements. 2 marks for the fact that the Traffic Contract defines the QoS requirements, 1 mark for the fact that the Traffic Contract needs to specify the traffic profile, 3 marks for specifying typical parameters any valid parameter will score 1 mark up to a maximum of 3. c) A TCP connection is uni-directional which means that for two way communications, a connection must be established from each side. Each process does however, follow the same three way handshake procedure. The end-station requesting the connection will issue a TCP segment with the SYN flag set and the sequence number equal to some initial value say x. The receiving end-station if it 3

4 wants to accept the connection request will return a TCP segment with both the SYN and ACK flags set. It will also choose a sequence number starting value say y. The acknowledgement field of this segment will be set to x+1 to acknowledge receipt of the connection request segment. When the requesting end-station receives this response it will issue one further TCP segment with the ACK field set. The acknowledgement in this segment will be y+1 and the sequence number will be x+1 2 marks for noting that TCP connections are uni-directional. 4 marks for TCP connection request (SYN, sequence number, direction), 4 marks for the TCP response (SYN+ACK, sequence number, acknowledgement number), 4 marks for TCP confirmation (ACK, sequence and acknowledgement numbers. A correctly labelled diagram would also attract full marks as an alternative. d) TCP is able to support protocol multiplexing. This means that more than one protocol can operate simultaneously above a single TCP layer. TCP is able to determine which higher layer protocol to direct traffic to by virtue of the port number used. Port numbers are 16 bits in length and some known as the well known ports are defined to represent certain protocols. For example port 80 = http. 2 marks for port numbers determine the higher layer protocol to use, 2 marks for well known ports being defined to represent standard protocols. Examiners comments: Students, when they were triggered to look at TCP connection establishment they faired well but many having done two previous questions on circuit establishment tried to relate concepts alien to TCP such as fixed route negotiation.. A significant number of students remained in x25 establishment mode and faired badly. The last sub-question is largely well done however some students whether conditioned from answering to low in the stack related port concepts to physical network devise ports and as expected a number see well known to be synonymous with frequently used. A3 4

5 Answer pointers a. It is often said that the Internet offers a best effort quality of service. What is meant by this term? (6 marks) b. What is meant by the term Virtual Private Network (VPN), and explain how it can be used to provide secure communications over the Internet. (9 marks) c. A salesman has been given a company laptop computer. They are currently attending a conference in another country but need to access their company s network and servers. Explain how; if they have access to the Internet, they could use a VPN to gain secure access their company s network. You may assume that the company network is also connected to the Internet via a Firewall. a) The Internet offers a best effort service which means that it does not guarantee: that data will reach the destination the time it will take for data to reach its destination that the transmission will be error free 2 marks each for delivery, time and errors b) A Virtual Private Network is a means of providing a private network connection over an open or public network. This is achieved through the establishment of virtual circuits or tunnels through the public network. In effect the VPN encapsulates a user s data within a large packet structure; the header of which provides identification. Networks which support VPNs can then use this VPN header to route the packets. The Internet is a shared and open network. A VPN can be established between two points to secure communications through the use a shared security protocol. Say you have two points A and B on the Internet and you wish to secure the communications between them. A and B will agree on a security protocol (encryption technique - IPsec) Information sent from A to B is then secured using this security protocol. Whilst that data is passed over the Internet and could be detected by others, it cannot be decoded without knowledge of the security protocol being used by A and B. The data being sent from B to A can use a different security protocol. VPN 2 marks for providing a private connection through a public network, 1 mark for tunnelling, 2 marks for VPN packet encapsulation. Secure communications 2 marks for the use of a shared security protocol between end points, 2 marks for data encryption. c) 5

6 The Laptop must be connected to an Internet service via a local ISP. The laptop can then communicate with the remote firewall. The laptop and firewall then form the two ends of a VPN and agree on a security protocol to adopt. However, in order to ensure that the laptop user is valid, the firewall will require some form of authentication before establishing the VPN. Once authenticated, data leaving the laptop will be encrypted using the agreed security protocol and decoded by the firewall. The firewall will then pass the data through to the company s main network and hence, through to the server or whatever the laptop user needs access to. Data sent back to the user is then encrypted by the firewall and decoded by the laptop. This VPN is then said to be tunnelled through the Internet. 1 mark for the laptop and firewall forming two ends of the VPN, 2 marks for firewall authentication, 2 marks for use of an agreed security protocol between the laptop and firewall, 2 marks for data being encrypted whilst sent over the Internet, 2 marks for firewall passing data through to the company s network and 1 mark for the VPN providing a tunnel through the Internet. Examiners comments: Some very good answers. Interesting a number of students opted not to attempt a perhaps indicative of a lack of familiarity with the concept. Some students describing or explicitly stating they were considering WLANs, in terms of some of the key concepts of path negotiation and security. Many students could only focus on secure web pages and their experience of HTTP and public key encryption. That said it scored highest and was the most popular question. Section B B4 IPv4 internetworks operated by a single organisation sometimes use distance vector protocols to manage the transfer of routing information. a) Briefly explain the behaviour of distance vector protocols and illustrate your answer by reference to RIP (Routing Information Protocol). (15 marks) b) What problems can arise with regard to the use of distance vector protocols in networks? Answer Pointers a) Distance vector protocols operate by routers making announcements of networks which they can reach together with the distance (metric) of their route to that destination [3 marks]. The announcements are normally made at regular fixed intervals, typically about once 6

7 every 30 seconds [3 marks]. The routers do not provide any detail of the nature of the routes being announced and thus some authors refer to DV as being routing by rumour [3 marks]. RIP is a DV protocol. RIPv1 is a fairly old protocol, although still in use. It does not support netmasks and can thus only be used with class based addressing [2 marks]. RIPv2 introduces support for netmasks and thus supports classless internet domain routing (CIDR) [2 marks] and also has a simple authentication mechanism [2 marks]. b) Two problems that occur with such DV protocols are the formation of routing loops [3 marks] and slow convergence [3 marks]. There are also potential security problems as it is fairly easy to set up a computer to introduce spurious messages (with RIPv1) [2 marks] and also as information is often broadcast (RIPv1) then traffic may have to be processed by devices that have no interest [2 marks]. Examiner s Comments: This question was attempted by about 52% of the candidates. A large number of candidates confused the activity of the creation and updating of routing tables with the activity of actual packet forwarding. The creation and updating of routing tables only happens only relatively rarely. As noted above, with the RIP versions of DV this is normally about once every 30 seconds or so. On the other hand, packet forwarding is a VERY regular activity, occurring once for every packet and it will use routing tables which have been created earlier. Part a) VERY clearly asks candidates to illustrate their answer by reference to RIP. A very large number of candidates made no reference to RIP at all. B5 Local Area Networks are often now constructed using wireless technologies, in particular, WiFi (IEEE ). a) Briefly explain the difference between the WiFi operational modes known as infrastructure and ad-hoc. b) Explain the problems created by the presence of what are normally called hidden nodes in a WiFi network. (8 marks) c) Explain why many WiFi networks can have a high error rate caused by cochannel interference. (7 marks) Answer Pointers a) The WiFi operational mode known as infrastructural is one where the devices in the network are considered to be of two types [2 marks]. One devices (possibly more) adopt the role of being access points (APs) [2 marks]. All the other devices are set so as they will only ever attempt to connect to APs [2 marks]. In the operational mode known as ad-hoc, all devices are considered to be similar [2 marks]. Thus, in ad-hoc mode, one device may connect to any other [2 marks]. b) WiFi networks are using wireless radio transmission. WiFi signals only have a limited range [2 marks]. It is thus possible (indeed common) that if an access point is located physically towards the centre of the network, it may be possible for two different devices to be happily able to talk to the access point even though there signals do not reach each other [4 marks]. The result of this is that the two nodes may keep corrupting each others signals (without them being aware) and thus the AP does not receive them correctly [2 marks]. 7

8 c) In most cases, WiFi networks are using wireless radio transmission in the 2.4Ghz band [2 marks]. This (largely unlicensed) frequency band is used by a large range of other equipment [2 marks] such as bluetooth, microwave ovens and so on [2 marks]. As these are all on similar frequencies, errors caused by this co-channel activity can be common [1 mark]. Examiner s Comments; This question was attempted by about 38% of the candidates. Many candidates did not have a clear understanding of the difference between ad-hoc and infrastructural modes of operation. Many of the answers to part b) incorrectly discussed the issue of unauthorised nodes attempting to intercept traffic rather than the discussing the issues given in the answer pointer above. WiFi networks have grown in practical importance over the last five years or so and candidates are advised to gain a good understanding. Some answers to part c) addressed the issues as expected while other answers were somewhat confused. B6 a) Signals moving over communications links can become modified in various ways. Explain the meaning of the terms attenuation, dispersion and noise in this context. (15 marks) b) Explain the difference between single bit and burst errors and the extent to which parity checking is appropriate as an error detecting technique in both cases. Answer Pointers a) Attenuation is the reduction in amplitude of a signal [3 marks]. This reduction in amplitude may mean signals are interpreted incorrectly at receivers unless amplifiers and/or repeaters are included at appropriate places [2 marks]. Dispersion is the spreading out of a signal in time [3 marks] this is caused as the speed of propagation of signals through medium changes with respect to frequency [2 marks]. Noise is the introduction of unwanted elements to the signal [3 marks]. The noise might come from external sources, but some may be due to molecular vibration of the medium (often called thermal noise) [2 marks]. b) Single bit errors are situations where an isolated bit is corrupt, but those around it are fine [2 marks] whereas burst errors are where a sequence of adjacent bits is all corrupted [2 marks]. Parity checking is quite appropriate for a situation where single bit errors are likely [2 marks] indeed, if both horizontal and vertical parity is used some errors can even be corrected [2 mark]. Parity checking is not really appropriate in situations where burst errors are likely [2 marks]. While parity checking may locate some errors, better techniques such as CRC checks are more appropriate if burst errors are likely to occur. Examiner s Comments: This question was attempted by about 85% of the candidates. Many candidates do not realise that the term thermal noise refers to the molecular vibration of the material but instead believe it is noise due to materials getting very hot. Thermal noise will be present in all materials unless they are at absolute zero. The amount of thermal noise will increase as material get hotter, but in practice it is always present at some level. It will of course be present in optical conductors as well as metallic conductors. Many of the answers offered concerning dispersion do not describe it correctly; candidates are referred to the answer pointers given above. 8

BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS. BCS Level 5 Diploma in IT APRIL 2013 COMPUTER NETWORKS EXAMINERS REPORT

BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS. BCS Level 5 Diploma in IT APRIL 2013 COMPUTER NETWORKS EXAMINERS REPORT BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS BCS Level 5 Diploma in IT APRIL 2013 COMPUTER NETWORKS EXAMINERS REPORT General Comments This session is again like the last September

More information

BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS. BCS Level 5 Diploma in IT SEPTEMBER 2014. Computer Networks EXAMINERS REPORT

BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS. BCS Level 5 Diploma in IT SEPTEMBER 2014. Computer Networks EXAMINERS REPORT BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS BCS Level 5 Diploma in IT SEPTEMBER 2014 Computer Networks EXAMINERS REPORT General Comments This session is again like the April

More information

BCS THE CHARTERED INSTITUTE FOR IT. BCS HIGHER EDUCATION QUALIFICATIONS BCS Level 5 Diploma in IT COMPUTER NETWORKS

BCS THE CHARTERED INSTITUTE FOR IT. BCS HIGHER EDUCATION QUALIFICATIONS BCS Level 5 Diploma in IT COMPUTER NETWORKS BCS THE CHARTERED INSTITUTE FOR IT BCS HIGHER EDUCATION QUALIFICATIONS BCS Level 5 Diploma in IT COMPUTER NETWORKS Friday 2 nd October 2015 Morning Answer any FOUR questions out of SIX. All questions carry

More information

(Refer Slide Time: 2:10)

(Refer Slide Time: 2:10) Data Communications Prof. A. Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture-12 Multiplexer Applications-1 Hello and welcome to today s lecture on multiplexer

More information

11/22/2013 1. komwut@siit

11/22/2013 1. komwut@siit 11/22/2013 1 Week3-4 Point-to-Point, LAN, WAN Review 11/22/2013 2 What will you learn? Representatives for Point-to-Point Network LAN Wired Ethernet Wireless Ethernet WAN ATM (Asynchronous Transfer Mode)

More information

Objectives. Remote Connection Options. Teleworking. Connecting Teleworkers to the Corporate WAN. Providing Teleworker Services

Objectives. Remote Connection Options. Teleworking. Connecting Teleworkers to the Corporate WAN. Providing Teleworker Services ITE I Chapter 6 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 1 Objectives Providing Teleworker Services Describe the enterprise requirements for providing teleworker services Explain how

More information

:-------------------------------------------------------Instructor---------------------

:-------------------------------------------------------Instructor--------------------- Yarmouk University Hijjawi Faculty for Engineering Technology Computer Engineering Department CPE-462 Digital Data Communications Final Exam: A Date: 20/05/09 Student Name :-------------------------------------------------------Instructor---------------------

More information

CTS2134 Introduction to Networking. Module 07: Wide Area Networks

CTS2134 Introduction to Networking. Module 07: Wide Area Networks CTS2134 Introduction to Networking Module 07: Wide Area Networks WAN cloud Central Office (CO) Local loop WAN components Demarcation point (demarc) Consumer Premises Equipment (CPE) Channel Service Unit/Data

More information

WAN Technology. Heng Sovannarith heng_sovannarith@yahoo.com

WAN Technology. Heng Sovannarith heng_sovannarith@yahoo.com WAN Technology Heng Sovannarith heng_sovannarith@yahoo.com Introduction A WAN is a data communications network that covers a relatively broad geographic area and often uses transmission facilities provided

More information

Public Switched Telephone System

Public Switched Telephone System Public Switched Telephone System Structure of the Telephone System The Local Loop: Modems, ADSL Structure of the Telephone System (a) Fully-interconnected network. (b) Centralized switch. (c) Two-level

More information

2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 D. None of the above

2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 D. None of the above 1. How many bits are in an IP address? A. 16 B. 32 C. 64 2. What is the maximum value of each octet in an IP address? A. 128 B. 255 C. 256 3. The network number plays what part in an IP address? A. It

More information

1 Introduction to mobile telecommunications

1 Introduction to mobile telecommunications 1 Introduction to mobile telecommunications Mobile phones were first introduced in the early 1980s. In the succeeding years, the underlying technology has gone through three phases, known as generations.

More information

Communication Networks. MAP-TELE 2011/12 José Ruela

Communication Networks. MAP-TELE 2011/12 José Ruela Communication Networks MAP-TELE 2011/12 José Ruela Network basic mechanisms Introduction to Communications Networks Communications networks Communications networks are used to transport information (data)

More information

Transport and Network Layer

Transport and Network Layer Transport and Network Layer 1 Introduction Responsible for moving messages from end-to-end in a network Closely tied together TCP/IP: most commonly used protocol o Used in Internet o Compatible with a

More information

Chapter 5. Data Communication And Internet Technology

Chapter 5. Data Communication And Internet Technology Chapter 5 Data Communication And Internet Technology Purpose Understand the fundamental networking concepts Agenda Network Concepts Communication Protocol TCP/IP-OSI Architecture Network Types LAN WAN

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

Data Transmission. Data Communications Model. CSE 3461 / 5461: Computer Networking & Internet Technologies. Presentation B

Data Transmission. Data Communications Model. CSE 3461 / 5461: Computer Networking & Internet Technologies. Presentation B CSE 3461 / 5461: Computer Networking & Internet Technologies Data Transmission Presentation B Kannan Srinivasan 08/30/2012 Data Communications Model Figure 1.2 Studying Assignment: 3.1-3.4, 4.1 Presentation

More information

Technical papers Virtual private networks

Technical papers Virtual private networks Technical papers Virtual private networks This document has now been archived Virtual private networks Contents Introduction What is a VPN? What does the term virtual private network really mean? What

More information

IT4504 - Data Communication and Networks (Optional)

IT4504 - Data Communication and Networks (Optional) - Data Communication and Networks (Optional) INTRODUCTION This is one of the optional courses designed for Semester 4 of the Bachelor of Information Technology Degree program. This course on Data Communication

More information

EECC694 - Shaaban. Transmission Channel

EECC694 - Shaaban. Transmission Channel The Physical Layer: Data Transmission Basics Encode data as energy at the data (information) source and transmit the encoded energy using transmitter hardware: Possible Energy Forms: Electrical, light,

More information

VoIP Bandwidth Considerations - design decisions

VoIP Bandwidth Considerations - design decisions VoIP Bandwidth Considerations - design decisions When calculating the bandwidth requirements for a VoIP implementation the two main protocols are: a signalling protocol such as SIP, H.323, SCCP, IAX or

More information

Post-Class Quiz: Telecommunication & Network Security Domain

Post-Class Quiz: Telecommunication & Network Security Domain 1. What type of network is more likely to include Frame Relay, Switched Multi-megabit Data Services (SMDS), and X.25? A. Local area network (LAN) B. Wide area network (WAN) C. Intranet D. Internet 2. Which

More information

High Performance VPN Solutions Over Satellite Networks

High Performance VPN Solutions Over Satellite Networks High Performance VPN Solutions Over Satellite Networks Enhanced Packet Handling Both Accelerates And Encrypts High-Delay Satellite Circuits Characteristics of Satellite Networks? Satellite Networks have

More information

Overview of Computer Networks

Overview of Computer Networks Overview of Computer Networks Client-Server Transaction Client process 4. Client processes response 1. Client sends request 3. Server sends response Server process 2. Server processes request Resource

More information

communication over wireless link handling mobile user who changes point of attachment to network

communication over wireless link handling mobile user who changes point of attachment to network Wireless Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers! computer nets: laptops, palmtops, PDAs, Internet-enabled phone promise anytime untethered Internet

More information

XDSL and DSLAM Access Technologies

XDSL and DSLAM Access Technologies XDSL and DSLAM Access Technologies Abstract What are the differences between the different forms of xdsl technology, such as ADSL and HDSL? How are they implemented. What are the limitations? What are

More information

WAN. Introduction. Services used by WAN. Circuit Switched Services. Architecture of Switch Services

WAN. Introduction. Services used by WAN. Circuit Switched Services. Architecture of Switch Services WAN Introduction Wide area networks (WANs) Connect BNs and LANs across longer distances, often hundreds of miles or more Typically built by using leased circuits from common carriers such as AT&T Most

More information

Long Distance Connection and WAN

Long Distance Connection and WAN Lecture 6 Long Distance Connection and WAN Digital Telephone, PCM and Nyquist Sampling Theorem DSU/CSU, T Line Series and OC line Series Local Loop DSL Technologies - ADSL, HDSL, SDSL, VDSL Cable Modem

More information

TECHNICAL CHALLENGES OF VoIP BYPASS

TECHNICAL CHALLENGES OF VoIP BYPASS TECHNICAL CHALLENGES OF VoIP BYPASS Presented by Monica Cultrera VP Software Development Bitek International Inc 23 rd TELELCOMMUNICATION CONFERENCE Agenda 1. Defining VoIP What is VoIP? How to establish

More information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information

Computer Network. Interconnected collection of autonomous computers that are able to exchange information Introduction Computer Network. Interconnected collection of autonomous computers that are able to exchange information No master/slave relationship between the computers in the network Data Communications.

More information

Attenuation (amplitude of the wave loses strength thereby the signal power) Refraction Reflection Shadowing Scattering Diffraction

Attenuation (amplitude of the wave loses strength thereby the signal power) Refraction Reflection Shadowing Scattering Diffraction Wireless Physical Layer Q1. Is it possible to transmit a digital signal, e.g., coded as square wave as used inside a computer, using radio transmission without any loss? Why? It is not possible to transmit

More information

Wireless Home Networking Fundamentals

Wireless Home Networking Fundamentals P a g e 1 Wireless Home Networking Fundamentals This course is designed to provide a comprehensive understanding of wireless home network fundamentals. Students will gain an understanding of: WiFi standards,

More information

R2. The word protocol is often used to describe diplomatic relations. How does Wikipedia describe diplomatic protocol?

R2. The word protocol is often used to describe diplomatic relations. How does Wikipedia describe diplomatic protocol? Chapter 1 Review Questions R1. What is the difference between a host and an end system? List several different types of end systems. Is a Web server an end system? 1. There is no difference. Throughout

More information

ADSL or Asymmetric Digital Subscriber Line. Backbone. Bandwidth. Bit. Bits Per Second or bps

ADSL or Asymmetric Digital Subscriber Line. Backbone. Bandwidth. Bit. Bits Per Second or bps ADSL or Asymmetric Digital Subscriber Line Backbone Bandwidth Bit Commonly called DSL. Technology and equipment that allow high-speed communication across standard copper telephone wires. This can include

More information

Chapter 2 - The TCP/IP and OSI Networking Models

Chapter 2 - The TCP/IP and OSI Networking Models Chapter 2 - The TCP/IP and OSI Networking Models TCP/IP : Transmission Control Protocol/Internet Protocol OSI : Open System Interconnection RFC Request for Comments TCP/IP Architecture Layers Application

More information

Wireless Networks. Reading: Sec5on 2.8. COS 461: Computer Networks Spring 2011. Mike Freedman

Wireless Networks. Reading: Sec5on 2.8. COS 461: Computer Networks Spring 2011. Mike Freedman 1 Wireless Networks Reading: Sec5on 2.8 COS 461: Computer Networks Spring 2011 Mike Freedman hep://www.cs.princeton.edu/courses/archive/spring11/cos461/ 2 Widespread Deployment Worldwide cellular subscribers

More information

CS263: Wireless Communications and Sensor Networks

CS263: Wireless Communications and Sensor Networks CS263: Wireless Communications and Sensor Networks Matt Welsh Lecture 4: Medium Access Control October 5, 2004 2004 Matt Welsh Harvard University 1 Today's Lecture Medium Access Control Schemes: FDMA TDMA

More information

SECTION 2 TECHNICAL DESCRIPTION OF BPL SYSTEMS

SECTION 2 TECHNICAL DESCRIPTION OF BPL SYSTEMS SECTION 2 TECHNICAL DESCRIPTION OF SYSTEMS 2.1 INTRODUCTION Access equipment consists of injectors (also known as concentrators), repeaters, and extractors. injectors are tied to the backbone via fiber

More information

Lab Exercise 802.11. Objective. Requirements. Step 1: Fetch a Trace

Lab Exercise 802.11. Objective. Requirements. Step 1: Fetch a Trace Lab Exercise 802.11 Objective To explore the physical layer, link layer, and management functions of 802.11. It is widely used to wireless connect mobile devices to the Internet, and covered in 4.4 of

More information

10CS64: COMPUTER NETWORKS - II

10CS64: COMPUTER NETWORKS - II QUESTION BANK 10CS64: COMPUTER NETWORKS - II Part A Unit 1 & 2: Packet-Switching Networks 1 and Packet-Switching Networks 2 1. Mention different types of network services? Explain the same. 2. Difference

More information

White Paper. D-Link International Tel: (65) 6774 6233, Fax: (65) 6774 6322. E-mail: info@dlink.com.sg; Web: http://www.dlink-intl.

White Paper. D-Link International Tel: (65) 6774 6233, Fax: (65) 6774 6322. E-mail: info@dlink.com.sg; Web: http://www.dlink-intl. Introduction to Voice over Wireless LAN (VoWLAN) White Paper D-Link International Tel: (65) 6774 6233, Fax: (65) 6774 6322. Introduction Voice over Wireless LAN (VoWLAN) is a technology involving the use

More information

Implementing Secured Converged Wide Area Networks (ISCW) Version 1.0

Implementing Secured Converged Wide Area Networks (ISCW) Version 1.0 COURSE OVERVIEW Implementing Secure Converged Wide Area Networks (ISCW) v1.0 is an advanced instructor-led course that introduces techniques and features that enable or enhance WAN and remote access solutions.

More information

Networked AV Systems Pretest

Networked AV Systems Pretest Networked AV Systems Pretest Instructions Choose the best answer for each question. Score your pretest using the key on the last page. If you miss three or more out of questions 1 11, consider taking Essentials

More information

This course has been retired. View the schedule of current <a href=http://www.ptr.co.uk/networkingcourses.htm>networking

This course has been retired. View the schedule of current <a href=http://www.ptr.co.uk/networkingcourses.htm>networking Introduction to Data Communications & Networking Course Description: This course has been retired. View the schedule of current networking Courses

More information

Chapter 9 Using Telephone and Cable Networks for Data Transmission

Chapter 9 Using Telephone and Cable Networks for Data Transmission 9-11 TELEPHONE NETWORK Chapter 9 Using Telephone and Cable Networks for Data Transmission 1 McGraw-Hill Copyright The McGraw-Hill Companies, Inc. Permission required The for reproduction McGraw-Hill or

More information

Network+ Guide to Networks, Fourth Edition. Chapter 7 WANs, Internet Access, and Remote Connectivity. Objectives

Network+ Guide to Networks, Fourth Edition. Chapter 7 WANs, Internet Access, and Remote Connectivity. Objectives Network+ Guide to Networks, Fourth Edition Chapter 7 WANs, Internet Access, and Remote Connectivity Objectives Identify a variety of uses for WANs Explain different WAN topologies, including their advantages

More information

IP Networking. Overview. Networks Impact Daily Life. IP Networking - Part 1. How Networks Impact Daily Life. How Networks Impact Daily Life

IP Networking. Overview. Networks Impact Daily Life. IP Networking - Part 1. How Networks Impact Daily Life. How Networks Impact Daily Life Overview Dipl.-Ing. Peter Schrotter Institute of Communication Networks and Satellite Communications Graz University of Technology, Austria Fundamentals of Communicating over the Network Application Layer

More information

IT4405 Computer Networks (Compulsory)

IT4405 Computer Networks (Compulsory) IT4405 Computer Networks (Compulsory) INTRODUCTION This course provides a comprehensive insight into the fundamental concepts in data communications, computer network systems and protocols both fixed and

More information

16.36 Communication Systems Engineering

16.36 Communication Systems Engineering MIT OpenCourseWare http://ocw.mit.edu 16.36 Communication Systems Engineering Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 16.36: Communication

More information

THE UNIVERSITY OF AUCKLAND

THE UNIVERSITY OF AUCKLAND COMPSCI 742 THE UNIVERSITY OF AUCKLAND SECOND SEMESTER, 2008 Campus: City COMPUTER SCIENCE Data Communications and Networks (Time allowed: TWO hours) NOTE: Attempt all questions. Calculators are NOT permitted.

More information

Computer Networking Networks

Computer Networking Networks Page 1 of 8 Computer Networking Networks 9.1 Local area network A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as a home, school, office

More information

ADSL part 2, Cable Internet, Cellular

ADSL part 2, Cable Internet, Cellular ADSL part 2, Cable Internet, Cellular 20 June 2016 Lecture 12 20 June 2016 SE 428: Advanced Computer Networks 1 Topics for Today ADSL Cable Internet Cellular Radio Networks 20 June 2016 SE 428: Advanced

More information

Digital Subscriber Line (DSL) Transmission Methods

Digital Subscriber Line (DSL) Transmission Methods Digital Subscriber Line (DSL) Transmission Methods 1. Overview... 1 2. SHDSL Transmission Methods... 1 SHDSL Transmission System Versions... 1 SHDSL Transmission Subsystem Structure... 1 SHDSL Modulation

More information

GPRS / 3G Services: VPN solutions supported

GPRS / 3G Services: VPN solutions supported GPRS / 3G Services: VPN solutions supported GPRS / 3G VPN soluti An O2 White Paper An O2 White Paper Contents Page No. 3 4-6 4 5 6 6 7-10 7-8 9 9 9 10 11-14 11-12 13 13 13 14 15 16 Chapter No. 1. Executive

More information

ECE/CS 372 introduction to computer networks. Lecture 13

ECE/CS 372 introduction to computer networks. Lecture 13 ECE/CS 372 introduction to computer networks Lecture 13 Announcements: HW #4 hard copy due today Lab #5 posted is due Tuesday June 4 th HW #5 posted is due Thursday June 6 th Pickup midterms Acknowledgement:

More information

Introduction Chapter 1. Uses of Computer Networks

Introduction Chapter 1. Uses of Computer Networks Introduction Chapter 1 Uses of Computer Networks Network Hardware Network Software Reference Models Example Networks Network Standardization Metric Units Revised: August 2011 Uses of Computer Networks

More information

Copyright. Transport networks. Physical layer Transport and access networks. Pag. 1

Copyright. Transport networks. Physical layer Transport and access networks. Pag. 1 Physical layer Transport and access networks Gruppo Reti TLC nome.cognome@polito.it http://www.telematica.polito.it/ COMPUTER NETWORK DESIGN Physical layer review - 1 Copyright Quest opera è protetta dalla

More information

Life of a Packet CS 640, 2015-01-22

Life of a Packet CS 640, 2015-01-22 Life of a Packet CS 640, 2015-01-22 Outline Recap: building blocks Application to application communication Process to process communication Host to host communication Announcements Syllabus Should have

More information

Process Control and Automation using Modbus Protocol

Process Control and Automation using Modbus Protocol Process Control and Automation using Modbus Protocol Modbus is the fundamental network protocol used in most industrial applications today. It is universal, open and an easy to use protocol. Modbus has

More information

FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2 nd ed. Chapter 2 An Introduction to Networking

FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2 nd ed. Chapter 2 An Introduction to Networking FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2 nd ed. Chapter 2 An Introduction to Networking Learning Objectives Upon completion of this chapter, you should be able to: Describe the

More information

Final for ECE374 05/06/13 Solution!!

Final for ECE374 05/06/13 Solution!! 1 Final for ECE374 05/06/13 Solution!! Instructions: Put your name and student number on each sheet of paper! The exam is closed book. You have 90 minutes to complete the exam. Be a smart exam taker -

More information

1. Public Switched Telephone Networks vs. Internet Protocol Networks

1. Public Switched Telephone Networks vs. Internet Protocol Networks Internet Protocol (IP)/Intelligent Network (IN) Integration Tutorial Definition Internet telephony switches enable voice calls between the public switched telephone network (PSTN) and Internet protocol

More information

SSVP SIP School VoIP Professional Certification

SSVP SIP School VoIP Professional Certification SSVP SIP School VoIP Professional Certification Exam Objectives The SSVP exam is designed to test your skills and knowledge on the basics of Networking and Voice over IP. Everything that you need to cover

More information

DESIGN AND VERIFICATION OF LSR OF THE MPLS NETWORK USING VHDL

DESIGN AND VERIFICATION OF LSR OF THE MPLS NETWORK USING VHDL IJVD: 3(1), 2012, pp. 15-20 DESIGN AND VERIFICATION OF LSR OF THE MPLS NETWORK USING VHDL Suvarna A. Jadhav 1 and U.L. Bombale 2 1,2 Department of Technology Shivaji university, Kolhapur, 1 E-mail: suvarna_jadhav@rediffmail.com

More information

SSVVP SIP School VVoIP Professional Certification

SSVVP SIP School VVoIP Professional Certification SSVVP SIP School VVoIP Professional Certification Exam Objectives The SSVVP exam is designed to test your skills and knowledge on the basics of Networking, Voice over IP and Video over IP. Everything that

More information

Advanced Higher Computing. Computer Networks. Homework Sheets

Advanced Higher Computing. Computer Networks. Homework Sheets Advanced Higher Computing Computer Networks Homework Sheets Topic : Network Protocols and Standards. Name the organisation responsible for setting international standards and explain why network standards

More information

Voice and Delivery Data Networks

Voice and Delivery Data Networks Voice and Delivery Data Networks Chapter 11 Learning Objectives After reading this chapter, you should be able to: Identify the basic elements of a telephone system Describe the composition of the telephone

More information

Hamilton County Communications, Inc. NETWORK POLICY AND PRACTICE FOR ISP. Table of Contents

Hamilton County Communications, Inc. NETWORK POLICY AND PRACTICE FOR ISP. Table of Contents Hamilton County Communications, Inc. NETWORK POLICY AND PRACTICE FOR ISP Table of Contents Section Page Definitions 2 Terms of Service and Network Management Practices 2 Devices & Software that may be

More information

Note! The problem set consists of two parts: Part I: The problem specifications pages Part II: The answer pages

Note! The problem set consists of two parts: Part I: The problem specifications pages Part II: The answer pages Part I: The problem specifications NTNU The Norwegian University of Science and Technology Department of Telematics Note! The problem set consists of two parts: Part I: The problem specifications pages

More information

Telecommunications, Networks, and Wireless Computing

Telecommunications, Networks, and Wireless Computing Objectives Telecommunications, Networks, and Wireless Computing 1. What are the features of a contemporary corporate telecommunications system? On what major technology developments are they based? 2.

More information

ICTTEN6172A Design and configure an IP- MPLS network with virtual private network tunnelling

ICTTEN6172A Design and configure an IP- MPLS network with virtual private network tunnelling ICTTEN6172A Design and configure an IP- MPLS network with virtual private network tunnelling Release: 1 ICTTEN6172A Design and configure an IP-MPLS network with virtual private network tunnelling Modification

More information

Next Generation of High Speed. Modems8

Next Generation of High Speed. Modems8 Next Generation of High Speed Modems High Speed Modems. 1 Traditional Modems Assume both ends have Analog connection Analog signals are converted to Digital and back again. Limits transmission speed to

More information

Chapter 9. Internet. Copyright 2011 John Wiley & Sons, Inc 10-1

Chapter 9. Internet. Copyright 2011 John Wiley & Sons, Inc 10-1 Chapter 9 Internet Copyright 2011 John Wiley & Sons, Inc 10-1 Outline 9.2 - How the Internet Works - Basic Architecture - Connecting to an ISP - Internet Today 9.3 - Internet Access Technologies - DSL

More information

Black Box Explains: DSL

Black Box Explains: DSL Black Box Explains: DSL History It was realized as early as the late eighties, early nineties, that conventional data transmission systems did not meet the requirements of the growing internet community

More information

TCP and Wireless Networks Classical Approaches Optimizations TCP for 2.5G/3G Systems. Lehrstuhl für Informatik 4 Kommunikation und verteilte Systeme

TCP and Wireless Networks Classical Approaches Optimizations TCP for 2.5G/3G Systems. Lehrstuhl für Informatik 4 Kommunikation und verteilte Systeme Chapter 2 Technical Basics: Layer 1 Methods for Medium Access: Layer 2 Chapter 3 Wireless Networks: Bluetooth, WLAN, WirelessMAN, WirelessWAN Mobile Networks: GSM, GPRS, UMTS Chapter 4 Mobility on the

More information

Public Network. 1. Relatively long physical distance 2. Requiring a service provider (carrier) Branch Office. Home. Private Network.

Public Network. 1. Relatively long physical distance 2. Requiring a service provider (carrier) Branch Office. Home. Private Network. Introduction to LAN TDC 363 Week 4 Connecting LAN to WAN Book: Chapter 7 1 Outline Wide Area Network (WAN): definition WAN Topologies Choices of WAN technologies Dial-up ISDN T1 Frame Relay DSL Remote

More information

Customer Interface Publication: CIP024

Customer Interface Publication: CIP024 Customer Interface Publication: CIP024 KCOM Group PLC DataLine Access Service Description and Technical Characteristics Issue: Version 1.2 April 2016 The information in this document is provided in accordance

More information

Multiplexing on Wireline Telephone Systems

Multiplexing on Wireline Telephone Systems Multiplexing on Wireline Telephone Systems Isha Batra, Divya Raheja Information Technology, Dronacharya College of Engineering Farrukh Nagar, Gurgaon, India ABSTRACT- This Paper Outlines a research multiplexing

More information

Communication Systems I

Communication Systems I Communication Systems I Course Map Contents Recap of the networks we ve seen so far Basics of protocols HTTP example The OSI model Packet and Circuit switching Physical media What to expect next Recap

More information

How DSL Works. by Curt Franklin

How DSL Works. by Curt Franklin by Curt Franklin How DSL Works When you connect to the Internet, you might connect through a regular modem, through a localarea network connection in your office, through a cable modem or through a digital

More information

ADSL BROADBAND BASICS FOR THE DOMESTIC USER. The Main Limitations of ADSL Broadband are as follows.

ADSL BROADBAND BASICS FOR THE DOMESTIC USER. The Main Limitations of ADSL Broadband are as follows. ADSL BROADBAND BASICS FOR THE DOMESTIC USER AS NOTHING MAN MADE IS PERFECT, ADSL IS NOT AN EXCEPTION. The Main Limitations of ADSL Broadband are as follows. 1. ADSL is not a Guaranteed Bandwidth Service.

More information

Protocol Data Units and Encapsulation

Protocol Data Units and Encapsulation Chapter 2: Communicating over the 51 Protocol Units and Encapsulation For application data to travel uncorrupted from one host to another, header (or control data), which contains control and addressing

More information

Nexus Technology Review -- Exhibit A

Nexus Technology Review -- Exhibit A Nexus Technology Review -- Exhibit A Background A. Types of DSL Lines DSL comes in many flavors: ADSL, ADSL2, ADSL2+, VDSL and VDSL2. Each DSL variant respectively operates up a higher frequency level.

More information

EE4367 Telecom. Switching & Transmission. Prof. Murat Torlak

EE4367 Telecom. Switching & Transmission. Prof. Murat Torlak Packet Switching and Computer Networks Switching As computer networks became more pervasive, more and more data and also less voice was transmitted over telephone lines. Circuit Switching The telephone

More information

Network+ Guide to Networks 6 th Edition. Chapter 7 Wide Area Networks

Network+ Guide to Networks 6 th Edition. Chapter 7 Wide Area Networks Network+ Guide to Networks 6 th Edition Chapter 7 Wide Area Networks Objectives Identify a variety of uses for WANs Explain different WAN topologies, including their advantages and disadvantages Compare

More information

Data Communication Networks and Converged Networks

Data Communication Networks and Converged Networks Data Communication Networks and Converged Networks The OSI Model and Encapsulation Layer traversal through networks Protocol Stacks Converged Data/Telecommunication Networks From Telecom to Datacom, Asynchronous

More information

WAN Data Link Protocols

WAN Data Link Protocols WAN Data Link Protocols In addition to Physical layer devices, WANs require Data Link layer protocols to establish the link across the communication line from the sending to the receiving device. 1 Data

More information

ENHWI-N3. 802.11n Wireless Router

ENHWI-N3. 802.11n Wireless Router ENHWI-N3 802.11n Wireless Router Product Description Encore s ENHWI-N3 802.11n Wireless Router s 1T1R Wireless single chip can deliver up to 3x faster speed than of 802.11g devices. ENHWI-N3 supports home

More information

Terms VON. VoIP LAN WAN CODEC

Terms VON. VoIP LAN WAN CODEC VON Voice Over the Net. Voice transmitted over the Internet. That is the technical definition. Prescient Worldwide s product, called VON, means Voice Over Network as in ANY network, whether a client s

More information

ADSL WAN Connections. Contents

ADSL WAN Connections. Contents 7 ADSL WAN Connections Contents ADSL Overview................................................. 7-4 ADSL Technologies.......................................... 7-5 ADSL2 and ADSL2+: Enhancing Transmission

More information

Data Networking and Architecture. Delegates should have some basic knowledge of Internet Protocol and Data Networking principles.

Data Networking and Architecture. Delegates should have some basic knowledge of Internet Protocol and Data Networking principles. Data Networking and Architecture The course focuses on theoretical principles and practical implementation of selected Data Networking protocols and standards. Physical network architecture is described

More information

Building integrated services intranets

Building integrated services intranets Building integrated services intranets A White Paper from Inalp Networks Inc Meriedweg 7 CH-3172 Niederwangen Switzerland http://www.inalp.com CONTENTS CONTENTS...2 1 EXECUTIVE SUMMARY...3 2 INTRODUCTION...4

More information

CSE 3461 / 5461: Computer Networking & Internet Technologies

CSE 3461 / 5461: Computer Networking & Internet Technologies Autumn Semester 2014 CSE 3461 / 5461: Computer Networking & Internet Technologies Instructor: Prof. Kannan Srinivasan 08/28/2014 Announcement Drop before Friday evening! k. srinivasan Presentation A 2

More information

DATA SECURITY 1/12. Copyright Nokia Corporation 2002. All rights reserved. Ver. 1.0

DATA SECURITY 1/12. Copyright Nokia Corporation 2002. All rights reserved. Ver. 1.0 DATA SECURITY 1/12 Copyright Nokia Corporation 2002. All rights reserved. Ver. 1.0 Contents 1. INTRODUCTION... 3 2. REMOTE ACCESS ARCHITECTURES... 3 2.1 DIAL-UP MODEM ACCESS... 3 2.2 SECURE INTERNET ACCESS

More information

Local Area Networks (LANs) Blueprint (May 2012 Release)

Local Area Networks (LANs) Blueprint (May 2012 Release) Local Area Networks (LANs) The CCNT Local Area Networks (LANs) Course April 2012 release blueprint lists the following information. Courseware Availability Date identifies the availability date for the

More information

Outlines. LECTURE 3: Wireless Transmission Technologies. Wireless Transmission on Unguided Media

Outlines. LECTURE 3: Wireless Transmission Technologies. Wireless Transmission on Unguided Media LECTURE 3: Wireless Transmission Technologies CIS 472 Wireless Communications and Networks Winter 2016 Instructor: Dr. Song Xing Outlines Wireless Data Transmission Modulation Spread Spectrum Department

More information

Network System Design Lesson Objectives

Network System Design Lesson Objectives Network System Design Lesson Unit 1: INTRODUCTION TO NETWORK DESIGN Assignment Customer Needs and Goals Identify the purpose and parts of a good customer needs report. Gather information to identify network

More information

Hello viewers, welcome to today s lecture on cellular telephone systems.

Hello viewers, welcome to today s lecture on cellular telephone systems. Data Communications Prof. A. Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture minus 31 Cellular Telephone Systems Hello viewers, welcome to today s lecture

More information

EDA 1200 4.3 Training Programs. Catalog of Course Descriptions

EDA 1200 4.3 Training Programs. Catalog of Course Descriptions EDA 1200 4.3 Training Programs Catalog of Course Descriptions Catalog of Course Descriptions INTRODUCTION...3 ACCESS NETWORKS, AN OVERVIEW...4 CORE NETWORKS, AN OVERVIEW...6 EDA 1200 4.3 INSTALLATION AND

More information

November 2013. Defining the Value of MPLS VPNs

November 2013. Defining the Value of MPLS VPNs November 2013 S P E C I A L R E P O R T Defining the Value of MPLS VPNs Table of Contents Introduction... 3 What Are VPNs?... 4 What Are MPLS VPNs?... 5 What Are the Benefits of MPLS VPNs?... 8 How Do

More information