Subject: [AVT] HTTP Trickplay

From: John Gildred <[email-masked]>
Date: Wed, 10 Dec 2003 10:02:51 -0800

Hello AVT:

Has anyone submitted an I-D in the past which defines a method of 
providing trickplay over HTTP (much like what RTSP can do)? For 
example, adding HTTP headers for playback position, speed, direction, 
etc.

-John Gildred
Vice President of Engineering
Pioneer Research Center USA, Inc.
A Division of Pioneer Electronics
101 Metro Drive, Suite 264
San Jose, California 95110
Office (408) 437-1800 Ext. 105
Mobile (510) 295-7770
[email-masked]

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: John Lazzaro <[email-masked]>
Date: Thu, 11 Dec 2003 09:41:58 -0800 (PST)

> John Gildred writes:
> providing trickplay over HTTP (much like what RTSP can do)?

From the MMUSIC minutes of IETF 51 (London):

========================================================================
10. Tunneling RTSP/RTP/RTCP in HTTP (draft-gentric-avt-rtsp-http-00.txt) 
========================================================================

RTSP describes a TCP-based streaming mode. This includes interleaved
RTP/RTCP packets. The draft proposal is to extend this to HTTP-only
firewalls.

Source of proposal: Internet Streaming Media Alliance.

The basic proposal is to use HTTP to create a channel in each
direction. The authors are looking for more ideas and thoughts on how
to proceed.

Melinda Shore ([email-masked]) expressed her disagreement with the
proposal, because it raises serious security concerns.  Its whole
thrust is to violating site security policy.  It would be more
consistent with network policy to use Jonathan's SIP approach. If the
draft is accepted, HTTP might become characterized as "Horrible
Trashcan Transport Protocol". Jonathan Rosenberg noted that it is too
late to salvage HTTP's reputation: RFC 3093 "IP Over HTTP" already
describes how to do it. Mark Handley also expressed his concern with
the security implications. Port 554 is allocated for RTSP; managers
can open it if they want to. Apparently some firewall vendors already
block strange uses of HTTP. Site administrators are aware of this sort
of tunneling and are asking firewall vendors for controls.

Joerg Ott ruled that the responses he had heard make it clear that the
proposal is going nowhere in the MMUSIC WG.

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John Lazzaro    http://www.cs.berkeley.edu/~lazzaro
     lazzaro [at] cs [dot] berkeley [dot] edu     
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