A Network Layer Approach to Enable TCP over Multiple Interfaces

The mobile Internet is set to become ubiquitous with the deployment of various wireless technologies. When heterogeneous wireless networks overlap in coverage, a mobile terminal can potentially use multiple wireless interfaces simultaneously. In this paper, we motivate the advantages of simultaneous use of multiple interfaces and present a network layer architecture that supports diverse multi-access services. Our main focus is on one such service provided by the architecture: Bandwidth Aggregation (BAG), specifically for TCP applications.While aggregating bandwidth across multiple interfaces can improve raw throughput, it introduces challenges in the form of packet reordering for TCP applications. When packets are reordered, TCP misinterprets the duplicate ACKS received as indicative of packet loss and invokes congestion control. This can significantly lower TCP throughput and counter any gains that can be had through bandwidth aggregation. To improve overall performance of TCP, we take a two-pronged approach: (1) We propose a scheduling algorithm that partitions traffic onto the different paths (corresponding to each interface) such that reordering is minimized. The algorithm estimates available bandwidth and thereby minimizes reordering by sending packet pairs on the path that introduces the least amount of delay. (2) A buffer management policy is introduced at the client to hide any residual reordering from TCP. We show through simulations that our network-layer approach can achieve good bandwidth aggregation under a variety of network conditions.

[1]  Jiebo Luo,et al.  Special issue: Multimedia over mobile IP , 2002, Wirel. Commun. Mob. Comput..

[2]  Raghupathy Sivakumar,et al.  A Transport Layer Approach for Achieving Aggregate Bandwidths on Multi-Homed Mobile Hosts , 2002, MobiCom '02.

[3]  Chieh-Yih Wan,et al.  Comparison of IP micromobility protocols , 2002, IEEE Wirel. Commun..

[4]  Kameswari Chebrolu,et al.  Multi-access services in heterogeneous wireless networks , 2004 .

[5]  Kameswari Chebrolu,et al.  Bandwidth aggregation for real-time applications in heterogeneous wireless networks , 2006, IEEE Transactions on Mobile Computing.

[6]  J. Duncanson,et al.  Inverse multiplexing , 1994, IEEE Communications Magazine.

[7]  Scott Shenker,et al.  Analysis and simulation of a fair queueing algorithm , 1989, SIGCOMM 1989.

[8]  Dhananjay S. Phatak,et al.  A novel mechanism for data streaming across multiple IP links for improving throughput and reliability in mobile environments , 2002, Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies.

[9]  Lixia Zhang,et al.  Stream Control Transmission Protocol , 2000, RFC.

[10]  Bernd Girod,et al.  Advances in channel-adaptive video streaming , 2002, Proceedings. International Conference on Image Processing.

[11]  Mark Allman,et al.  On making TCP more robust to packet reordering , 2002, CCRV.

[12]  Randy H. Katz,et al.  Vertical handoffs in wireless overlay networks , 1998, Mob. Networks Appl..

[13]  Srinivasan Keshav.  A control-theoretic approach to flow control , 1991, SIGCOMM 1991.

[14]  Randy H. Katz,et al.  The effects of asymmetry on TCP performance , 1997, MobiCom '97.

[15]  Sally Floyd,et al.  Simulation-based comparisons of Tahoe, Reno and SACK TCP , 1996, CCRV.

[16]  Ming Zhang,et al.  Improving TCP’s Performance under Reordering with DSACK , 2007 .

[17]  Rui Zhang,et al.  Advances in channel-adaptive video streaming , 2002, Wirel. Commun. Mob. Comput..

[18]  Randy H. Katz,et al.  The effects of asymmetry on TCP performance , 1999, Mob. Networks Appl..

[19]  Charles E. Perkins,et al.  Mobile IP , 1997, IEEE Communications Magazine.

[20]  Robin Kravets,et al.  Transport level mechanisms for bandwidth aggregation on mobile hosts , 2001, Proceedings Ninth International Conference on Network Protocols. ICNP 2001.

[21]  R. Srikant,et al.  Fair scheduling in wireless packet networks , 1999, TNET.

[22]  George Varghese,et al.  A Reliable and Scalable Striping Protocol , 1996, SIGCOMM.

[23]  Mark Allman,et al.  An Application-Level solution to TCP''s Satellite Inefficiencies , 1996 .

[24]  Robert L. Grossman,et al.  PSockets: The Case for Application-level Network Striping for Data Intensive Applications using High Speed Wide Area Networks , 2000, ACM/IEEE SC 2000 Conference (SC'00).

[25]  Brian Lloyd,et al.  The PPP Multilink Protocol (MP) , 1994, RFC.

[26]  Kameswari Chebrolu,et al.  Communication using multiple wireless interfaces , 2002, 2002 IEEE Wireless Communications and Networking Conference Record. WCNC 2002 (Cat. No.02TH8609).

[27]  Ciro D'Apice,et al.  Queueing Theory , 2003, Operations Research.

[28]  A. Acharya,et al.  A Study of Internet Round-trip Delay , 1998 .

[29]  James Aweya,et al.  A self-regulating TCP acknowledgment (ACK) pacing scheme , 2002, Int. J. Netw. Manag..