QoS Routing (QoSR)



Motivation

In IP networks, providing quality guaranteed services is becoming a principle demand for network operators. Routing plays an important role with other technologies (e.g., traffic engineering) in efficiently managing limited network resources. QoS based routing, as well called constraint based routing, is needed in all aspects of routing, e.g., routing algorithms,  route optimization algorithms, routing management, etc. This requires broad and deep investigations on QoSR in IP networks, especially QoS based IP networks.

We go deep in the following sub-topics:

Architecture for QoSR
DiffServ and MPLS are two architectures that will mostly use QoSR, however, not limited to these two.

QoSR in DiffServ

DiffServ describes a network with edge routers and core routers. It differentiates various services by tagging a DiffServ code point (DSCP) to each packet at edge routers and forwarding the packet according to its DSCP and agreed per-hop behavior (PHB). Guaranteeing quality for specific traffic requires provisioning consistent PHBs in networks, in turn, requires abundant network resources along a path or multiple paths. Since network resources are generally limited, there is a need for the efficient management of routes, as well as network resources (e.g., buffer, bandwidth, etc.).

QoSR in MPLS

In principle, MPLS is able to guarantee quality for per-flow which is unique transmitted on a label switch path (LSP). Setting up an explicit path needs the support of QoSR protocols.

QoSR protocols

A feasible way to develop QoSR protocols is based on existing routing protocols, e.g., OSPF, BGP. The QoSR protocols are to provide single or multiple routes according to QoS requirements as well as network statistics. A QoSR protocol provides interfaces to get, manage and configure routes as well as policies.

QoSR algorithms

QoSR algorithms must be simple and efficient enough. They should be stable and robust against heterogeneous network environments and traffic variation. The algorithms include:

Simulation tools and software     Note that both are public software with free source code. And here are some routing software:
  • Alternate Queuing (ALTQ): with many kinds of traffic engineering mechanisms including CBQ, HFSC, WFQ, etc for BSD Unix. It has already been used in our lab for experiments.
  • Zebra: GNU routing software for FreeBSD, Linux.
  • Gated: Not so free
  • Publications Search engines for references     Report new engines, click here.

    Useful Links
    There are a number of useful links good to check:

        Report new links, click here.

    Coming conferences
    There are always some valuable conferences worth for submission.

    Any ideas or suggestions, please email to pgzhang@tct.hut.fi.

    Latest modified on 09.02.2002 Maintained by Peng Zhang