1. Modeling and Simulating MPLS Networks
Azeddien M. Sllame
Computer Network Department
Faculty of Information Technology
University of Tripoli
Tripoli, Libya

2. Paper goal
This paper describes modeling and simulation tools that are used to evaluate MPLS-based networks
GNS3 could be used in designing and modeling computer networks; while Wireshark can enhance the protocols investigation process
OpenSimMPLS tool which enable the designers to make the modeling & simulation as an interactive process
OPNET tool: VOIP application is examined on MPLS network and compared with IP network

3. MPLS
Multiprotocol Label Switching (MPLS) is an evolving technology that
Assures permanent and steady delivery of the Internet services with high transmission speed and lower delays
MPLS features
lower network delay
efficient forwarding technique
Scalability
guaranteed performance of the services
Hence, this makes MPLS
An effective implementation for backbone communication and computer networks

4. MPLS network 1_ Label creation and distribution
2_ Table creation at each router
3_ Label-switched path creation
4_ Label insertion/table lookup
5_ Packet forwarding

5. Tools of interest ((GNS3))
is used to simulate networks with elements of different wide area networks (WAN) technologies such as frame relay and ATM
GNS3 supports IOS routers, Ethernet switches and PIX firewalls
virtual machines and devices images during simulation process
GNS3 can capture packets on a capture file for further use and analysis with applications like Wireshark

6. GNS3 example : MPLS network
MPLS domain

7. The following is a sample of configuring MPLS protocol for router R1 using GNS3
hostname R1
interface FastEthernet0/0
ip address
duplex auto
speed auto
mpls label protocol ldp
tag-switching mtu 1512
tag-switching ip

8. The following is a sample of showing MPLS and LDP protocols configurations on the router R1 using GNS3
R1#show mpls ldp neighbor
Peer LDP Ident: :0;
Local LDP Ident :0
TCP connection:
State: Oper; Msgs sent/rcvd: 31/31;
Downstream Up time: 00:12:38
LDP discovery sources:
FastEthernet0/0,Src IP addr:
Addresses bound to peer LDP Ident:

9. Figure shows the LDP messaging that is used for label exchange process

10. EIGRP and LDP hello messages in MPLS domain

11. Tools of interest: OpenSimMPLS simulator
Developed as multiplatform software at University of Extremadura in Spain
It assists students to animatedly interact with the simulation
allows visual designing of scenes
guarantee of service technology simulation
Using this tool designers can see
packets flow
packets rerouting due to node congestion
packets rerouting due to link failures
Node’s buffer overflow
show the simulation course events step by step

12. Tools of interest: OpenSimMPLS simulator

13. OpenSimMPLS simulator: figure shows LSP paths and their backup paths that are created by MPLS domain routers

14. OpenSimMPLS simulator: node configurations

15. OpenSimMPLS simulator: link failure between Nalut) and Garyan:

16. OpenSimMPLS simulator: Node congestion in the case study

17. Tools of interest :OPNET
applied in advanced computer network courses
By using this tool students will gain well insight practical knowledge by modeling their computer network projects in depth
OPNET allows students to examine the application behavior and the background traffic of the designed network
advanced applications such as VOIP and multimedia streaming behaviors in different computer networks can be studied effectively

18. OPNET Example: VOIP case study

19. The configuration of the MPLS network topology
Six router LERs (R1, R2, R3, R4, R5 and R6) normal IP routers with MPLS enabled feature;
Four routers LSRs in the middle with light gray color (MPLS_R1, MPLS_R3, MPLS_R3 and MPLS_R4);
Two VOIP stations (VOIP_West and VOIP_East).

20. OPNET: some of VOIP app. results
The VOIP parameters are: call rate=500 calls/hour
with using G.711encoder,
average call duration=300s (5 min)
voice flow duration: s (25 min) for the experiment;
encoder scheme is interactive voice with delay, throughput and reliability including overhead (bytes) of RTP/UDP/IP protocols.

21. OPNET: some of VOIP app. results
Figure shows: VOIP
Packet delay variation
(Red for IP, Blue for MPLS)
Figure shows: VOIP
Packet End-to-End delay
(Red for IP, Blue for MPLS)

22. OPNET: some of VOIP app. results
Figure shows: VOIP
delay Jitter (sec) with PQ queuing
(Red for IP, Blue for MPLS)
Figure shows: VOIP Packet End-to-End delay using WFQ queuing mechanism (Red for IP, Blue for MPLS)

23. Conclusions
This paper highlighted MPLS-based networks which is now considered as an effective implementation for backbone communication and computer networks
The main goal of this paper is to show the different capabilities of a three different modeling and simulation tools in modeling and simulating MPLS-based networks
These tools can be used in hands-on projects by students in project-based learning in computer network courses to enhance students’ skills in solving real network design problems

24. Thank you

25. The following protocols are incorporated in the OpenSimMPLS in addition to the MPLS protocol
•Tiny Label Distribution Protocol (TLDP): it incorporates a reduced set from LDP it is the main MPLS signaling protocol in which the label mapping information is exchanged between LSRs. It is responsible in establishing and maintaining labels.
•GoS PDU Store and Retransmit Protocol (GPSRP) support: this protocol comprises of supporting GoS over MPLS. It allows making local retransmission of privileged packets when they are discarded in buffers nodes. However, this feature is only available for active nodes.
•Dynamic Memory for GoS (PDU) (DMGP) implementation: this component belongs to the proposal of supporting GoS over MPLS. DMGP node is a node internal memory that allows the temporary storage of the privileged packets that are switched by the node. This makes possible their later retransmission if necessary. This feature is available only for active nodes.