TCP flow aware adaptive path switching in diffserv enabled MPLS networks

Date
2011-03-04
Authors
Alparslan, O.
Akar, N.
Karasan, E.
Advisor
Supervisor
Co-Advisor
Co-Supervisor
Instructor
Source Title
European Transactions on Telecommunications
Print ISSN
1124-318X
Electronic ISSN
Publisher
Wiley
Volume
22
Issue
5
Pages
185 - 199
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Series
Abstract

We propose an adaptive flow-level multi-path routing-based traffic engineering solution for an IP backbone network carrying TCP/IP traffic. Incoming TCP flows are switched between two explicitly routed paths, namely the primary and secondary paths (PP and SP), for resilience and potential goodput improvement at the TCP layer. In the proposed architecture, PPs receive a preferential treatment over SPs using differentiated services mechanisms. The reason for this choice is not for service differentiation but for coping with the detrimental knock-on effect stemming from the use of longer SP that is well known for conventional network load balancing algorithms. Moreover, both paths are congestion-controlled using Explicit Congestion Notification marking at the core and Additive Increase Multiplicative Decrease rate adjustment at the ingress nodes. The delay difference between PP and SP is estimated using two per-egress rate-controlling buffers maintained at the ingress nodes for each path, and this delay difference is used to determine the path over which a new TCP flow will be routed. We perform extensive simulations using ns-2 in order to demonstrate the viability of the proposed distributed adaptive multi-path routing method in terms of per-flow TCP goodput. The proposed solution consistently outperforms the single-path routing policy and provides substantial per-flow goodput gains under poor PP conditions. Moreover, highest goodput improvements under the proposed scheme are achieved by flows that receive the lowest goodputs with single-path routing, while the performance of the flows with high goodputs with single-path routing does not deteriorate with the proposed path switching technique.

Course
Other identifiers
Book Title
Keywords
Differentiated services, MPLS, Multi-path routing, Path switching, Traffic engineering
Citation
Published Version (Please cite this version)