Bandwidth Management in MPLS Networks

Transcription

1 School of Electronic Engineering - DCU Broadband Switching and Systems Laboratory 1/17 Bandwidth Management in MPLS Networks Sanda Dragos & Radu Dragos Supervised by Dr. Martin Collier dragoss@eeng.dcu.ie dragosr@eeng.dcu.ie collierm@eeng.dcu.ie

2 Current status of communication networks Before building the network of the future, we must first understand what exist. S. Keshav 2/17 The telephone network Offers end-to-end quality-of-service guarantees. The Internet Is more flexible and cheaper.

3 Motivation We all expect something more from communication networks. 3/17 Internet users: want better Internet services. Internet Service Providers: want to be able to provide better services.

4 Approaches Design a network that combines: the flexibility and low cost of the Internet with the end-to-end quality-of-service guarantees of the telephone network. 4/17 1. Create a new network: ATM (Asynchronous Transfer Mode) 2. Add quality-of-service mechanism to the Internet.

5 Bandwidth Management controls the bandwidth allocated to applications, users, and organizations sharing the same intranet or Internet link 5/17 A good Bandwidth Manager should: 1. enable full control of network traffic 2. ensure the availability of bandwidth for critical applications 3. increase network efficiency and reduce traffic congestion

6 Traffic Engineering (TE) 6/17 measuring and optimizing the performance of operational networks The key goals of TE: minimization of packet loss minimization of delay maximization of throughput enforcement of Service Level Agreements (SLAs)

7 Traffic Engineering Process Model 7/17 Define the relevant control policies Feedback mechanism Analize network state Performance optimization of the network Network

8 Label Switching paradigm 8/17 IPv4 Longest Prefix Match Address Mask OUT Interface = eth eth eth eth3 Exact Match Label IN IN interface Label OUT OUT interface 21 eth0 88 eth1 34 eth1 100 eth2 56 eth0 27 eth3 Labeled packet

9 MultiProtocol Label Switching (MPLS) Emerged from: need for a faster routing mechanism for IP and need to provide ATM switches with the control and scalability of a layer3 router 9/17 LER LER LSR - Label Switch Router LER - Label Edge Router LSP - Label Switch Path LER LSR LSP LSR MPLS cloud LER LER LSR LER

10 MPLS & Traffic Engineering MPLS is useful for TE in the specific aspects of measurement and dynamic control of Internet traffic. 10/17 the path (LSP) followed by a packet is determined at the ingress of an MPLS domain TE provided using explicit routed paths LSPs are independently created based on user-defined policies RSVP-TE and CR-LDP are two possible approaches to supply dynamic traffic engineering and QoS

11 Using MPLS to integrate IP with ATM & Frame Relay Combine Layer 2 switching & Layer 3 routing 11/17... IPv4 IPv6 IPX MPLS ATM Frame Relay PPP Ethernet... Layer 3 Network Layer 2 Data Link

12 Our project 12/17 Regular IP stack Active IP Text Active MPLS MPLS Networking Software ATM Packet Filter Ethernet Packet Filter Device Drivers

13 Implementing MPLS in Linux 13/17 Standard approach Layer 2 Header TextText MPLS shim Layer 3 Header 32b... Label Exp S TTL Our approach Layer 2 Header Ethernet 20b 48b Layer 3 Header 3b Destination Address Source Addres Packet type ID 24b Layer 4 Header 48b 1b 20b 8b... 16b 3b OUI Prefix Label COS S 1b

14 Advantages of using MPLS as a module 14/17 - in source implementation - kernel recompilation - system restart New Linux Kernel with MPLS support 1 IP router Linux Kernel loading MPLS module 2 MPLS Module IP router + MPLS switch unloading MPLS module Linux Kernel MPLS Module IP router

15 Network test suite 15/17 Internet IP 1 eth0 serial 0 IP 2 eth0 eth2 serial 0 eth0 MPLS 1 eth1 eth1 MPLS cloud MPLS 2 eth0 LAN hub UTP Patch Cord UTP Cross Connect MPLS Tunnel Serial line for remote kernel debugging

16 Simplified network test suite 16/17 LAN 1 (IPv4) LAN 2 (IPv4) LER 1 MPLS cloud LER 2

17 Conclusions & future work 17/17 Implementing MPLS understanding Linux OS internals understanding label switching paradigm and MPLS concepts useful research tool for future work (traffic engineering, bandwidth management, etc.) Future work Signaling protocol for our vanilla MPLS implementation Perform traffic engineering tasks using MPLS environment