[Dart] WGLC: draft-ietf-dart-dscp-rtp-02
Gorry Fairhurst <gorry@erg.abdn.ac.uk> Wed, 13 August 2014 20:33 UTC
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Date: Wed, 13 Aug 2014 21:33:06 +0100
From: Gorry Fairhurst <gorry@erg.abdn.ac.uk>
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Subject: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02
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I can see good points raised on the details, instead I have some questions about the overall document strcuture: (1) This statement appears at the end of section 2: "Multiplexing may reduce the complexity and resulting load on an endpoint. A single instance of STUN/ICE/TURN is simpler to execute and manage than multiple instances STUN/ICE/TURN operations happening in parallel, as the latter require synchronization and create more complex failure situations that have to be cleaned up by additional code." I suspect this is all true, but I'd like to ask that section 4 also makes a similar summary claim at the end - saying that using a single 5 tuple and multiplexing multiple streams with *different* QoS expectation and therefore different DSCP markings can complicate the transport protocol design, by requiring a transport to disambiguate the congestion state for each network QoS category that is used. It will also result in increased complexity at the transport layer to validate path integrity, where a 5-tuple could result in a different routing/forwarding path in order to validate that the individual 5-tuples are reachable. Of course, using DSCPs with an AF class can reduce some of the latter costs. etc according to what the draft says. I don't suggest that the extra complexity and additional algorithms are as big a problem as being unable to get through a NAPT/Firewall, but it seems that this nonetheless extra stuff that I don't recall having been worked upon before in the IETF - and a challenge I guess for the RMCAT WG. (2) I don't know if the document's goal is also to make transport recommendations for using multiple code points - i.e.things such as must be robust to the network changing a DSCP; needs to independently verify that a particular DCSP is not being black-holed, needs to not imply relative precedence when interpreting loss or marking of packets for a flow using multiple DCSPs etc. ??? If these are out of scope, then maybe the document should say that this particular document does not provide this sort of guidance. Gorry
- [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ben Campbell
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ruediger.Geib
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Black, David
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Brian E Carpenter
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ruediger.Geib
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Brian E Carpenter
- Re: [Dart] [rtcweb] Fwd: WGLC: draft-ietf-dart-ds… Dave Taht
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ruediger.Geib
- [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Gorry Fairhurst
- Re: [Dart] [rtcweb] Fwd: WGLC: draft-ietf-dart-ds… Brian E Carpenter
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ruediger.Geib
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 gorry
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Brian E Carpenter
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ruediger.Geib
- Re: [Dart] [AVTCORE] WGLC: draft-ietf-dart-dscp-r… Colin Perkins
- Re: [Dart] [AVTCORE] WGLC: draft-ietf-dart-dscp-r… Ben Campbell
- Re: [Dart] [AVTCORE] WGLC: draft-ietf-dart-dscp-r… Black, David
- Re: [Dart] WGLC: draft-ietf-dart-dscp-rtp-02 Ben Campbell