[Iccrg] ICCRG review of draft-sridharan-tcpm-ctcp-02
lachlan.andrew@gmail.com (Lachlan Andrew) Thu, 18 December 2008 00:08 UTC
From: lachlan.andrew@gmail.com
Date: Thu, 18 Dec 2008 00:08:34 +0000
Subject: [Iccrg] ICCRG review of draft-sridharan-tcpm-ctcp-02
In-Reply-To: <b98e548c0812171413n6914f4e8oda3b7831711bcf37@mail.gmail.com>
References: <B5A5E01F9387F4409E67604C0257C71E8AF7CC@NDJSEVS25A.ndc.nasa.gov> <b98e548c0812171413n6914f4e8oda3b7831711bcf37@mail.gmail.com>
Message-ID: <aa7d2c6d0812171621g50be8474xe490c7eb343f2673@mail.gmail.com>
X-Date: Thu Dec 18 00:08:34 2008
Greetings Saverio, That is a good point, but the self-induced losses are similar to standard TCP for typical buffer sizes. Although we didn't include specific figures for retransmissions, Fig 9(a) our PFLDnet paper <http://netlab.caltech.edu/lachlan/abstract/HybridPFLDnet08.pdf> shows that it shares bandwidth equally with standard TCP, which implies that it is not introducing more losses than another standard flow would. It's mechanism is different from purely loss-based proposals which are simply more aggressive. It is aggressive only when there is no detectable delay. If the buffer size is less than one or two packets per flow, it may be slightly more aggressive. However, if the flows all have low BDPs then it won't be much more aggressive (i.e., similar retransmission rate). Conversely, if they have large BDPs then CTCP will get much higher throughput than standard TCP, because standard TCP needs a large buffer when the per-flow BDP is large. Cheers, Lachlan 2008/12/18 Saverio Mascolo <saverio.mascolo@gmail.com>: > did someone measure goodput and retransmissions? TCPs using a more > aggressive probing than VJ TCP usually seem to end up - in good > cases- with similar goodput but at the expense of larger packet > retransmissions, which is not good! > -saverio -- Lachlan Andrew Centre for Advanced Internet Architectures (CAIA) Swinburne University of Technology, Melbourne, Australia <http://caia.swin.edu.au/cv/landrew> <http://netlab.caltech.edu/lachlan> Ph +61 3 9214 4837
- [Iccrg] ICCRG review of draft-sridharan-tcpm-ctcp… Lachlan Andrew
- [Iccrg] ICCRG review of draft-sridharan-tcpm-ctcp… Saverio Mascolo
- [Iccrg] ICCRG review of draft-sridharan-tcpm-ctcp… Eddy, Wesley M. GRC-RCN0[VZ]