[Trigtran] TRIGTRAN protocol principles and considerations - "set a bit"
Gorry Fairhurst <gorry@erg.abdn.ac.uk> Wed, 19 March 2003 15:43 UTC
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Date: Wed, 19 Mar 2003 07:39:07 -0800
Subject: [Trigtran] TRIGTRAN protocol principles and considerations - "set a bit"
From: Gorry Fairhurst <gorry@erg.abdn.ac.uk>
To: trigtran@ietf.org
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draft-dawkins-trigtran-framework-00.txt A few late, but short, queries/comments. 1) Section 4: I don't quite understand what you mean by point 3 in your list: "* Trigger coverage requests and notification requests will be piggy-backed on existing traffic ("setting a bit")." Can you be a bit (sorry about the pun) more explicit. You seem to be hinting at a mechanism that I do not yet understand. 2) Section 5: "Trigger: Connectivity Restored", following receipt of this event you suggest that it is safe to "Probe" for connectivity, the sender also has to decide an appropriate (conservative) RTO value to use, if this probe is successful. Setting the correct RTO may need to be considered carefully - since, if many PRTTs have passed, you no longer have an accurate view of the RTT, and perhaps you need to be even more conservative if the restored path could have been a result of a change in the link(s) being used. 3) Section 7.1: The motivation for a sender to process and utilise ICMP source quench messages was also somewhat unclear at the time. Senders had no incentive to respond to ICMP source quench messages - if they did so, they were being "polite" to other network users, but did not themselves necessarily see decreased delay or increased throughput. In a shared bottleneck topology, those senders that responded to ICMP source quench would likely experience reduced capacity as a result. IMHO the incentive to use this was not correct. The incentive to use was better for PMTU-D, since larger MSS (or less fragmentation) improved TCP performance. 4) Section 7.2: Perhaps it would be useful to also note the need to think about the issues concerning traversal of NAT, NAT-PT and TCP-PEP. I can't see that these are show-stoppers in any way, since the triggers themselves are advisory, and the discussion covering firewalls may also be approriate to these issues, at least at a top level. Gorry Fairhurst _______________________________________________ Trigtran mailing list Trigtran@ietf.org https://www1.ietf.org/mailman/listinfo/trigtran
- [Trigtran] TRIGTRAN protocol principles and consiā¦ Gorry Fairhurst