Datacom Services Description and their applications

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1 Datacom Services Description and their applications What is data communication services? Data communication ( datacom ) is range of services that will help organise communication and data exchange between two and more geographically separated points in Yerevan. This range of services is provided on OSI Layer 2, and allows for sophisticated applications such as interconnection of two or more office s located independent of each other, into one single Local Area Network. This can be achieved by establishing either point-to-point or multi-point datacom services. Hence, there is no need to use Internet for interconnecting offices and locations, datacom is the more secure and effective solution. Point to Point connections A simplest datacom service is presented in Drawing 1. This is the so-called E-pipe (Ethernet pipe) service, also known as VPWS (Virtual Pseudo Wire Service) or VLL (Virtual Leased Line) Service. ADC Network MPLS Core Drawing 1: E-pipe (VPWS/VLL) service Virtual leased line Epipe (VPWS/VLL) This type of service provides a point-to-point Ethernet connectivity from one location to another. As the line does not need to be physically separated from other network lines, it is named Virtual Leased Line or Virtual Pseudo Wire Service. This type of service provides a dedicated Ethernet bandwidth completely isolated from any other services provided through the same MPLS core. The service is based on an MPLS tunnel providing sophisticated capabilities for QoS shaping and redundancy throughout the entire network. The E-pipe service can be tuned according to needs by requesting the throughput speed most suitable for the type of traffic to be running on the E-pipe. Normally the E-pipe service provided has symmetric bandwidth, i.e identical for both directions from to B. However, it is still possible to have a customised solution with asymmetric bandwidths. Please contact ADC sales staff for tailored solutions and further assistance.

2 Point to Multi-point Services E-pipe Mesh solution for multi-point interconnection. It is possible to have point-to-multi-point interconnection between different locations. Depending on the exact needs, multiple E-pipe services can be used to create a desirable interconnection mesh (see Drawing 2). Alternatively VPLS services can be configured as described later in this document. Crossconnect of Epipe 1 & Epipe 2 Site C V aware switch V 1/Epipe 1 V 2/Epipe 2 Physica l Connec tion ADC Network MPLS Core Drawing 2: E-pipe Mesh Virtual leased line Epipe (VPWS/VLL) Please note from the drawing above that three different locations (, B and C) have been connected to each other only using a mesh of E-pipe lines, whereas on each site different E-pipe services have been delivered by just one physical connection. However, it is possible to differentiate them by using a V aware Layer 2 switch. Such a solution makes it possible to configure the switch in a way that each E-pipe line terminates on one physical port of the switch. Please contact our sales staff for more detailed and customized solution scenarios. As for the point-to-point scenario, each individual E-pipe can be fine-tuned for individual and specific needs. A service price list for standard service configurations are listed on For non-standard and customized configurations, please contact our sales staff for additional information. VPLS solution for multi-point interconnection Virtual Private Service belongs to the family of PPVPN services providing sophisticated features for interconnection of several enterprise-distributed points. With this type of L2 VPN service in place, the distributed points are connected as if they would be connected

3 to a L2 switch. When using VPLS services, the ADC network appears as one big and fully featured switch from a customer point of view. This imaginary switch supports functionalities like MAC learning, ARP proxying, Vs etc. When connecting access points using this method, they will all appear to be on the same without any additional local configuration requirements. There is no limit to number of interconnection points. In the Drawing 3 below there are just three points interconnected. Site C Virtual Private Lan Service (VPLS) ADC Network MPLS Core Drawing 3: VPLS Solution VPLS services provide the flexibility of choosing interconnection bandwidths in different access points. For example, you can choose to have 6 Mb/s bandwidth in Site C and B, but have 8 Mb/s connection bandwidth in if you know that B and C communicate more with A than with each other. In Drawing 4 the same VPLS structure as in Drawing 3 is illustrated, only with bandwidths specified. As three sites are connected with each other, and between sites B and C the bandwidth enabled is 2Mb/s, between sites A<>B and A<>C the available bandwidth is 4Mb/s. In order to satisfy aggregated bandwidth distribution requirements, there is a need to configure maximum 8 Mb/s in and 6 Mb/s for B and C. It is, however, possible to have a more flexible configuration based on bandwidth requirement specifics. This is discussed in more details in the QoS section of this document.

4 Site C 4 Mb/s 2Mb/s 4Mb/s 4 Mb/s to SiteA 2 Mb/s to SiteC Total 6Mb/s Drawing 4: VPLS Bandwidth distribution E-pipe Mesh vs. VPLS based multi-point solution Now we would like to take a more detailed look into two proposed multi-point solutions to highlight differences and the pros. and cons. for each particular solution. With E-pipe mesh there is sufficient flexibility to tailor WAN structure in preferable way and according to your particular needs. Virtual Leased Lines may be used to interconnect using existing self-owned equipment should this be in use for various networking purposes today. For example, in the case represented in Drawing 2, the interconnection between Sites B and C can be skipped. Instead two E-pipes can be used, one from to B and another one from to C. Then the interconnection of B and C can be organised in using self-owned equipment that is installed as shown in the Drawing 2: "Cross-connect of E-pipe 1 and E-pipe 2". This does imply that all inter-communication between Sites B and C will go through A, thus there is a need for more bandwidth on each E-pipe connecting to A in order to forward the traffic between the two other sites. Usually the E-pipe mesh solution is prefered when creating a Star topology WAN. VPLS gives more flexibility when planning and booking bandwidth between multiple locations. In the case depicted in Drawing 4, less than 8 Mb/s in may be booked for the two other sites connecting to A, thus sharing the bandwidth available on. As opposed to the E-pipe, VPLS is a multi-point solution allowing bandwidth booked in one point to be shared by access from all other points. Instead of 8 Mb/s in, 6 Mb/s may be sufficient. The only drawback is when both sites B and C try to perform data communication with A simultaneously, they will share the same 6 Mb/s.

5 Depending on the expected and distributed traffic patterns, custom tailored solutions can be made with even more sophisticated distribution and traffic prioritisation scenarios. This is further described in QoS section of this document. QoS and its applications Besides the fact that bandwidth is allocated for interconnection of geographically distributed points, the datacom services mix can be optimised according to specified needs. ADC can assign priorities to data flows based on a large variety of criteria. Booked bandwidth pipes can be converted into a number of sub-pipes with different bandwidths and scalability requirements. Drawing 5 illustrates an example configuration of the VPLS connection scenario depicted in Drawing 4. This is a hierarchical QoS configuration allowing to distribute the bandwidth available on among other sites in a very flexible way. Example QoS configuration for : Voice traffic between and A may receive 1 Mb/s of reserved bandwidth. Video traffic between and A receives 2 Mb/s, and data traffic is allowed 1 Mb/s reserved bandwidth. In direction to site C voice bandwidth reserved is 0.5 Mb/s, video bandwidth is 1 Mb/s, and another 0.5 Mb/s is reserved for data traffic. Now please pay attention to the PIR=MAX set for data traffic to both sites, as well as to the PIR=MAX set for the overall traffic to both sites. This means that as soon as i.e. video bandwidth between B and C is not in use, the data traffic between those two sites can occupy the residual. This is still not the complete story, the same happens with bandwidth pipes allocated for bandwidth needs to each direction. As soon as there is no data traffic from B to A, the bandwidth from B to C can scale up and take over the unused part of overall booked bandwidth (6 Mb/s). This optimises the economy of use as everything not being consumed by one traffic component can be consumed by another. Voice Video Data Voice Video Data PIR=1Mb/s CIR=1Mb/s PIR=2Mb/s CIR=2Mb/s PIR=MAX CIR=1Mb/s PIR=0,5 Mb/s CIR=0,5 Mb/s PIR=1Mb/s CIR=1Mb/s PIR=M AX CIR=0,5M b/s PIR=MAX CIR=4 Mb/s to SiteA PIR=MAX CIR=2 Mb/s to SiteC Total PIR 6Mb/s Drawing 5: H-QoS configuration While this is a particular example depicting a specific situation it is nearly impossible to envisage all possible configurations and tuning scenarios. To elaborate your network

6 planning, please contact our sales staff. QoS with encrypted traffic If traffic encryption is used, it is still possible to perform QoS traffic shaping. In order to make it happen you have to provide some way of traffic coloring. This can be done simply by encapsulating traffic in V tags and assigning different V IDs to different flows. This identifies which V carries which type of traffic, and appropriate priority may be assigned to each part. Datacom versus IPSec VPNs Why is there a real difference between PPVPNs (provider provisioned VPN) and CPVPNs (customer provisioned VPN also known as IPSec VPNs)? And why is it not possible to do all the same using IPSec VPNs? The main difference is the fact that PPVPNs are based on service provider's equipment, and this usually exists within one service provider network domain. With correct equipment in place, the QoS and traffic priority parameters can be tracked throughout the complete path of packet traversal. In IPSec VPNs the traffic may flow through different provider networks where each network has its own policies and traffic forwarding rules. Although it is possible to set some priorities on end points of an IPSec VPN, it is still impossible to guarantee that these priorities will be honoured throughout the complete packet traversal path. ADC offers datacom services with traffic shaping and priority tracking capabilities with QoS guarantees all the way from Service Ingress point up to the Service Egress point.