Objective#######################

Scenario to demonstrate conventional IGP Routing---------------------------------------------------------IGP_RoutingThis scenario demonstrates the conventional IGP used forrouting. In this scenario, the nodes are not configuredto use Multi Protocol Label Switching (MPLS).

Scenario to demonstrate Traffic Engineering (TE)----------------------------------------------------TE_Improve_UtilizationsThis scenario demonstrates the use of Traffic Engineering,to better route the traffic along the desired routes.MPLS LSPs are used to specify the routes.

As expected, Traffic Engineered network has betterthroughputs then the one without TE.

Scenario using MPLS with Differentiated Services-----------------------------------------------------

MPLS_with_DiffservIn this scenario, MPLS LSPs carrying more than one flowsuse DiffServ codes to assign different QoS levels to different flows.

Scenario using Label Distribution Protocol with CSPF-----------------------------------------------------LDP_With_CSPFThis scenario demonstrates the use of Label DistributionProtocol (LDP), along with Constrained Shortest PathFirst (CSPF) for Dynamic Route setups when Dynamic MPLSLSPs are used instead of Static LSPs.

Scenario using RSVP-TE with Fast Reroute-----------------------------------------------------RSV_TE_with_Fast_RerouteThis Scenario illustrates the use of RSVP-TE to configureLSPs Dynamicaly, and Use of Fast Reroute to protect LSPs locally.

Bypass Tunnel has been configured and Fast Reroute is usedto back up LSP at time of link failure in the network.##############################################################

Node Models Required--------------------

Wokstation:

Any workstation can be used to generate traffic over the network.

Server: In a client-server architecture, a workstation connects to server for traffic exchange.

Label Edge Router (LER):LER is the edge router used at the ingress and egress point of theMPLS LSPs.

Most of the TE and FEC bindings are done at the Ingress LER. The LER is responsible for pushing and popping the SHIM Label onto each packetentering the LSP.

Label Switching Router (LSR):LSRs are the intermediate routers used along the Label Switched Path.

The LSRs are responsible for swaping the SHIM Label onto each packetgoing through the LSP.

Note: Any Router in OPNET can be used as LER or LSR. i.e. all routers have MPLS configuration capability.

MPLS Config:This node is used to configure Forwarding Equivalence Class (FEC)and Traffic Trunk specifications. These specifications are associatedwith different flows at the ingress LERs, to differentiate the flowsinto various classes and different QoS agreements.

---------------------------------------------------------------------------------------------------FEC Specifications:------------------Used to specify different Forwarding Equivalence Classesto be used in the network. These configurations should bemade on the MPLS Config Object. Different FECs can bespecified depending upon one or nore combinations of ToS,Protocol used, Source/Destination Address, Source/DestinationPort etc.

Traffic Trunk Profiles:----------------------Traffic Trunk Profiles are specified at the MPLS Config Object.Various Traffic Trunks with different Maximum, average bit rates,and out of profile actions can be specified here. Each Traffictrunk is assigned a DiffServ Class.

MPLS Parameters:---------------Used to specify the MPLS parameters to be used. MPLS parameters should be configured at the Label Edge andLabel Switching Routers.

Traffic Engineering Configuration:---------------------------------TE Configurations are done at the Ingress Label Edge Routers (LERs).These configurations are used to perform the traffic bindings.Diferent FEC and Traffic Trunk specifications can be bind todifferent incoming interfaces at the Router, and they can beassigned to various LSPs.

LDP Parameters:--------------This attribute is used to configure the Label Distribution Protocol(LDP) parameters while using Dynamic LSPs.

Neighbour discovery timers, Keep Alive Message timers and Recovery parameters can be specified over here. These configurations shouldbe made on all LERs and LSRs while using Dynamic LSPs.##########################################################################

LSPs Delay Measurement (seconds)-------------------------------- LSP Delay (seconds):This statistic can be used to measure End-to-End Delay.It records the delay experienced by Packet in the LSP.i.e. Time spent by the packet within the Label Switched Path. Flow Delay (seconds):This statistic can be used to measure End-to-End Delay.It records the delay experienced by packet belonging to aspecific flow in the LSP. i.e. Time spent by a packet of a given flow inside the Label Switched Path.

Amount of Traffic entering and leaving the LSPs

----------------------------------------------- Traffic In (bits/second and packets/second):Total Traffic sent into the LSP at the ingress endof the tunnel.

Traffic Out (bits/second and packets/second):Total Traffic received from the LSP at the egress end of the tunnel.

Flow Traffic In (bits/second and packets/second):Traffic sent into the LSP at the ingress end of thetunnel for each flow that is carried through this Label Switched Path. Flow Traffic Out (bits/second and packets/second):Traffic received from the LSP at the egress end ofthe tunnel for each flow that is carried through this Label Switched Path.

Utilization of LSPs (Only Dynamic LSPs)----------------------------------

Utilization:Utilization is computed as a percentage of the throughputon the LSP to the amount of Bandwidth allocated when the LSP was setup.

Utilization is not be reported if the LSP does not haveany constraint to being with and the utilization could be more than 100% if the actual traffic uses more than what was intially reserved.

Flow Utilization:Flow Utilization is computed as a percentage of the throughputof a particular flow on the LSP to the amount of Bandwidthallocated when the LSP was setup.

The statistic is reported for each flow that is carried throughthe Label Switched Path.(i.e., a value indicating how much of the allocated bandwidth is used by any given flow)##############################################################################

FEC: Forwarding Equivalence Class: Class assigned to traffic based on various traffic attributes. This class is used to forward the trafficthrough different LSPs.

LDP: Label Distribution Protocol: Provides an LSR "discovery" mechanismto enable LSR peers to find each other and establish communication.

CSPF: Constrained Shortest Path First: An algorithm to compute a path forDynamic LSPs such that path is optimal with respect to some scaler metrics (e.g., minimizes administrative metric, hop count) and doesnot violate a set of constraints on that LSP

Static LSPs: Label Switched Path configured specifying all the intermediate hops

Dynamic LSPs: Label Switched Path configured specifying only the edge routers orsome of the intermediate routers. i.e end-to-end path is loosely defined.######################################################################

Scenario 1IGP_Routing

NETWORK INFO============This network illustrates a typical WAN configuration.

A> Background Traffic has been configured from

1> Site 1 --> Site 7 and Site 10 2> Site 2 --> Site 7 and Site 11 3> Site 3 --> Site 8 and Site 14 4> Site 4 --> Site 11 and Site 13 5> Site 5 --> Site 7 6> Site 6 --> Site 9

B> All edge links are DS3 and Core links are OC3 links.

C> No MPLS has been configured in the network.

RESULTS ANALYSIS: IGP_Routing

=======================================

Throughputs on different links have been shown.

Results show that as there is no Traffic Engineering being done,there are certain links with Throughput Zero.############################################################

2

NETWORK INFO============This Scenario illustrates the use of Traffic Engineering usingMPLS to route the traffic in the network to obtain better throughputs.

A> Background Traffic has been configured from

1> Site 1 --> Site 7 and Site 10 2> Site 2 --> Site 7 and Site 11 3> Site 3 --> Site 8 and Site 14 4> Site 4 --> Site 11 and Site 13 5> Site 5 --> Site 7 6> Site 6 --> Site 9

B> All edge links are DS3 and Core links are OC3 links.

C> MPLS has been configured in the network. Two FECs have been specified based on the destination address and thus all the traffic going to Site 7 and Site 14 have been routed through diffrent LSPs.

RESULTS ANALYSIS: TE_Improve_Utilizations=======================================

Throughputs on different links have been shown.

Results show that by doing some Traffic Engineering using MPLSthere has been a great change in link Throughputs across the network.Even the links which were not utilized earlier are used, thus increasing overall network Throughputs.#########################################################################3NETWORK INFO============This Scenario illustrates the use of MPLS to classify different flowsin the LSP, assign them DiffServ Codes and serve them with different QoS Levels.

A> Traffic has been configured from

1> Site 3 --> Site 14

2> Site 4 --> Site 14

B> All links are DS0 links.

C> MPLS has been configured in the network. Two Traffic Trunk Profiles have been specified with different DiffServ codes and the traffic flows from Site 3 and 4 are bind to different trunk profiles at the Ingress LER.

D> Routers are configured to perform Weighted Fair Queuing (WFQ).

RESULTS ANALYSIS: MPLS_with_Diffserv=======================================

Upload Response Time, Queuing Delay and Queuing Buffer usage.

Results show that even though two similar traffic are flowingto same destination but as different Traffic Trunk Profiles have been assigned to these flows thus the flow with higher DiffServ code has less Upload Response Time, less Queuing Delayand less Queuing Buffer usage.

Thus, MPLS can be used to assign different Service Level agreements.##############################################################################4NETWORK INFO============This Scenario illustrates the use of LDP and CSPF to configure LSPs Dynamicaly.

A> Traffic has been configured from

1> Birmingham --> Seattle 2> Houston --> San Jose 3> Los Angeles --> Seattle and New York 4> San Jose --> Tampa

B> All edge links are OC3 and Core links are DS3 links. The ATM core links are OC3.

C> MPLS has been configured in the network. Dynamic LSPs are configured by just specifying the Ingress and the Egress Routers. All the constrained path selection is done by LDP and CSPF.

D> Routers are configured to use LDP for neighbour discovery.

E> Constraints have been set up on some LSPs in order to illustrate that the normal IGP routes need not be used by CSPF if constraints are not met.

- Birmingham to Seattle: The color Blue is excluded in its resource class configuration. This color is supported by the interfaces connecting Atlanta to Dallas and Oklahoma City. Therefore, this LSP takes a longer route. - Houston to San Jose: This LSP is configured to have a bandwidth requirement of 1 Mbps. The sub-interface connecting Dallas to Salt Lake City is on the shortest path, but it is configured with a bandwidth metric of 500 Kbps, which is insufficient for the LSP. Hence the LSP is routed via Denver. The sub-interfaces that are used to route the LSP have a default bandwidth metric, which is equal to the links connected to the parent interfaces.

RESULTS ANALYSIS: LDP_with_CSPF=======================================

Traffic In and Out of the LSPs in the network have been shown.

With the use of LDP and CSPF, just Ingress and Egress Routers arespecified and all the constrained path selection is performed automatically. In cases where the shortest path does not satisfy the configured constraints, the best suitable path is selected.

The LSP from Birmigham to Seattle is routed via Washington DC sincethe links from Atlanta to Dallas and Oklahoma City support a resourceclass that is excluded on the LSP.

The LSP from Houston to San Jose is routed on the sub-interface connecting Dallas to Denver and then on to Salt Lake City, sincethe sub-interface connecting Dallas to Salt Lake City has a configuredbandwidth of 500 Kbps, which is too less for the LSP.###############################################################5NETWORK INFO============This Scenario illustrates the use of RSVP-TE to configure LSPs Dynamicaly. And Use of Fast Reroute to protect LSPs locally.

A> Traffic has been configured from

1> San Francisco --> Maine 2> Los Angeles --> Maine

B> All links are OC3 links.

C> MPLS has been configured in the network. Two Primary Dynamic LSPs are configured from Las Vegas to Boston via Houston.

D> One Primary LSP use Ingress initiated Backup LSP for protection and other primary LSP use a Bypass Tunnel to protect locally.

E> Routers are configured to use RSVP-TE for setting up LSPs.

F> Link between "Cincinnati to Washington" fails at time 450 seconds.

RESULTS ANALYSIS: RSVP-TE with Fast Reroute=======================================

1> Traffic reroute time has been shown for the primary LSPs.

Results show that for LSP that is using Fast Reroute for protection with Bypass Tunnels, Traffic reroute time is almost 10 times less then the Traffic reroute time for LSP that use Ingress initiated Backup LSP.

2> Traffic In of the LSPs in the network have also been shown.

Results show that Traffic is immediately bypassed using Bypass Tunnel for the LSP that uses Fast Reroute.

Whereas, Traffic is switched to backup LSP some time after failure, for LSP that use Ingress initiated Backup LSP.

##############################################################################

VPN

PROJECT DESCRIPTION===================This project illustrates some of the various technologies that can be used to set up Virtual Private Networks (VPNs). A brief description of the scenariosis given here.

Note: Each scenario contains a detailed description of that particular setup.

VPNs using IP Tunnels=====================The scenario "VPNs_with_IP_Tunnels" illustrates the use of layer-3 tunnels (GRE/IP-IP) to connect remote sites to a headquarters site. IGP routing protocols like EIGRP, OSPF etc can be run on the tunnels to exchange routinginformation between the various VPN sites.

MPLS/BGP VPNs=============These VPNs are based on RFC-2547. MPLS is used for forwarding packets overthe backbone, and BGP is used for distributing routes over the backbone. Thisproject contains two scenarios that illustrate MPLS/BGP VPNs. In the scenario"MPLS_VPNs_with_Static_Routes", static routes are used to announce the

customer edge (CE) routes into the VRFs. In the scenario "MPLS_VPNs_with_BGP",EBGP is used as the PE-CE (provider edge - customer edge) protocol.

Note: To return to the top level, right click on theblank screen and select "Go to Parent Subnet"

####################################################################MPLS_VPN_with_SR

Network Configuration

NETWORK INFO============This Scenario illustrates the use VPNs for communication between severaldifferent sites.

Two different Enterprise networks have been shown: Enterprise A and Enterprise B.

Enterprise A uses a VPN named "YELLOW_VPN" and Enterprise B uses a VPN named "RED_VPN" to communicate between different sits.

A> Background Traffic has been configured from

1> Enterprise A: Site 1: A_1_Rtr1 --> Enterprise A: Site 2: A_2_Rtr1 2> Enterprise B: Site 1: B_1_Rtr1 --> Enterprise B: Site 2: B_2_Rtr1

B> All links are PPP_SONET_OC3 links.

C> LSPs has been configured between each PE in the network.

D> BGP is configured between all PEs, i.e. all PEs are BGP neighbors.

E> Routes between PE and CE have been statically configured.

F> All sites in Enterprise A are configured to use "YELLOW_VPN" and all sites in Enterprise B are configured to use "RED_VPN".

RESULTS ANALYSIS: VRF Tables============================

VRF tables created by Site1_PE are shown here. (VRF tables can be exported to Simulation Log)

Comparing the two VRF tables show that:

1> Enterprise A and Enterprise B are using same address spaces and have similar IP addresses across the network.

2> As, VPNs are being used, the labels (Bottom Label) being assigned to entries in the VRF tables are different. This isolates traffic from YELLOW_VPN and RED_VPN.

3> The VRF Tables show, a> Destination Address b> Next BGP Hop address, i.e. next PE. c> Bottom Labels, to differentiate the VPNs d> Top Labels to be used to move traffic across the LSPs.

======================================================================================================

VRF TABLE snapshot for:

Router name: Logical Network.Site1_PE at time: 3600.00 seconds

VRF TABLE contents:

VRF Table for VPN <YELLOW_VPN> at Logical Network.Site1_PE:

Destination Subnet Mask Next BGP Hop Out Iface Bottom Label Top Label

----------- ----------- ------------ --------- ------------ --------- 192.0.31.0 255.255.255.0 192.0.17.2 IF0 31 UNDEF 192.0.33.0 255.255.255.0 192.0.17.2 IF0 32 UNDEF 192.0.32.0 255.255.255.0 192.0.17.2 IF0 33 UNDEF 192.0.28.0 255.255.255.0 192.0.14.1 IF2 31 34 192.0.29.0 255.255.255.0 192.0.14.1 IF2 32 34 192.0.30.0 255.255.255.0 192.0.14.1 IF2 33 34 192.0.34.0 255.255.255.0 192.0.16.2 IF2 31 31 192.0.35.0 255.255.255.0 192.0.16.2 IF2 32 31 192.0.36.0 255.255.255.0 192.0.16.2 IF2 33 31

VRF Table for VPN <RED_VPN> at Logical Network.Site1_PE:

Destination Subnet Mask Next BGP Hop Out Iface Bottom Label Top Label

----------- ----------- ------------ --------- ------------ --------- 192.0.31.0 255.255.255.0 192.0.100.11 IF3 34 UNDEF 192.0.32.0 255.255.255.0 192.0.100.11 IF3 35 UNDEF 192.0.33.0 255.255.255.0 192.0.100.11 IF3 36 UNDEF 192.0.28.0 255.255.255.0 192.0.14.1 IF2 34 34

192.0.29.0 255.255.255.0 192.0.14.1 IF2 35 34 192.0.30.0 255.255.255.0 192.0.14.1 IF2 36 34 192.0.34.0 255.255.255.0 192.0.16.2 IF2 34 31 192.0.35.0 255.255.255.0 192.0.16.2 IF2 35 31 192.0.36.0 255.255.255.0 192.0.16.2 IF2 36 31

#######################################################################

MPLS_VPN_with_BGP

NETWORK INFO============This Scenario illustrates the use VPNs for communication between severaldifferent sites.

Two different Eneterprise networks have been shown: Enterprise A and Enterprise B.

Enterprise A uses a VPN named "YELLOW_VPN" and Enterprise B uses a VPN named "RED_VPN" to communicate between different sits.

A> Background Traffic has been configured from

1> Enterprise A: Site 1: A_1_Rtr1 --> Enterprise A: Site 2: A_2_Rtr1 2> Enterprise B: Site 1: B_1_Rtr1 --> Enterprise B: Site 2: B_2_Rtr1

B> All links are PPP_SONET_OC3 links.

C> LSPs has been configured between each PE in the network.

D> BGP is configured between all PEs, i.e. all PEs are BGP neighbors.

E> Routes between PE and CE are shared using BGP, i.e. PEs and CEs are BGP neighbors of each other.

F> All sites in Enterprise A are configured to use "YELLOW_VPN" and all sites in Enterprise B are configured to use "RED_VPN".

RESULTS ANALYSIS: VRF Tables============================

VRF tables created by Site1_PE are shown here. (VRF tables can be exported to Simulation Log)

Comparing the two VRF tables show that:

1> Enterprise A and Enterprise B are using same address spaces and have similar IP addresses across the network.

2> As, VPNs are being used, the labels (Bottom Label) being assigned to entries in the VRF tables are different. This isolates traffic from YELLOW_VPN and RED_VPN.

3> The VRF Tables show, a> Destination Address b> Next BGP Hop address, i.e. next PE. c> Bottom Labels, to differentiate the VPNs d> Top Labels to be used to move traffic across the LSPs.

======================================================================================================VRF TABLE snapshot for:

Router name: Logical Network.Site1_PE at time: 3600.00 seconds

VRF TABLE contents:

VRF Table for VPN <YELLOW_VPN> at Logical Network.Site1_PE:

Destination Subnet Mask Next BGP Hop Out Iface Bottom Label Top Label

----------- ----------- ------------ --------- ------------ --------- 192.0.4.0 255.255.255.0 192.0.17.2 IF0 37 UNDEF 192.0.2.0 255.255.255.0 192.0.17.2 IF0 38 UNDEF 192.0.31.0 255.255.255.0 192.0.17.2 IF0 39 UNDEF 192.0.3.0 255.255.255.0 192.0.17.2 IF0 40 UNDEF 192.0.33.0 255.255.255.0 192.0.17.2 IF0 41 UNDEF 192.0.32.0 255.255.255.0 192.0.17.2 IF0 42 UNDEF 192.0.7.0 255.255.255.0 192.0.25.1 IF2 31 34 192.0.6.0 255.255.255.0 192.0.25.1 IF2 32 34 192.0.28.0 255.255.255.0 192.0.25.1 IF2 33 34 192.0.5.0 255.255.255.0 192.0.25.1 IF2 34 34 192.0.30.0 255.255.255.0 192.0.25.1 IF2 35 34 192.0.29.0 255.255.255.0 192.0.25.1 IF2 36 34 192.0.21.0 255.255.255.0 192.0.26.1 IF2 33 31 192.0.19.0 255.255.255.0 192.0.26.1 IF2 34 31 192.0.34.0 255.255.255.0 192.0.26.1 IF2 35 31 192.0.20.0 255.255.255.0 192.0.26.1 IF2 36 31 192.0.36.0 255.255.255.0 192.0.26.1 IF2 37 31 192.0.35.0 255.255.255.0 192.0.26.1 IF2 38 31

VRF Table for VPN <RED_VPN> at Logical Network.Site1_PE:

Destination Subnet Mask Next BGP Hop Out Iface Bottom Label Top Label

----------- ----------- ------------ --------- ------------ --------- 192.0.4.0 255.255.255.0 192.0.100.11 IF3 31 UNDEF 192.0.2.0 255.255.255.0 192.0.100.11 IF3 32 UNDEF 192.0.231.0 255.255.255.0 192.0.100.11 IF3 33 UNDEF 192.0.3.0 255.255.255.0 192.0.100.11 IF3 34 UNDEF 192.0.33.0 255.255.255.0 192.0.100.11 IF3 35 UNDEF 192.0.32.0 255.255.255.0 192.0.100.11 IF3 36 UNDEF 192.0.7.0 255.255.255.0 192.0.25.1 IF2 37 34 192.0.6.0 255.255.255.0 192.0.25.1 IF2 38 34 192.0.228.0 255.255.255.0 192.0.25.1 IF2 39 34 192.0.5.0 255.255.255.0 192.0.25.1 IF2 40 34 192.0.30.0 255.255.255.0 192.0.25.1 IF2 41 34 192.0.29.0 255.255.255.0 192.0.25.1 IF2 42 34 192.0.21.0 255.255.255.0 192.0.26.1 IF2 39 31 192.0.19.0 255.255.255.0 192.0.26.1 IF2 40 31 192.0.234.0 255.255.255.0 192.0.26.1 IF2 41 31 192.0.20.0 255.255.255.0 192.0.26.1 IF2 42 31 192.0.36.0 255.255.255.0 192.0.26.1 IF2 43 31 192.0.35.0 255.255.255.0 192.0.26.1 IF2 44 31

##########################################################################