Subject: sap specs and implementations

From: Markus Buchhorn <[email-masked]>
Date: Fri, 07 Jul 2000 11:32:17 +1000

G'day All

I've just been working on a (perl) sap listener and decoder, and following
the latest sap-v2 (-06) draft. This has led to a couple of questions :-)

Firstly - what other sap announcers are out there? I can see plenty of
versions of sdr sending sapv0 and sapv1/2 packets, and I think also Peter's
mstar stuff, but no others. I'm looking for some to test my decoder
against, and also test the authentication parts (which sdr doesn't appear
to let me get at). (At the same time what listeners are there? I'm also
writing a sap announcer, so need somebody else to check against.)

Second - does *anybody* actually use the msg id hash field as they "SHOULD"
(and also not set it to zero as they "SHOULD" not)?

Finally - a tiny comment on the draft. In section 5 under Session
Modification, it says 

>A pre-announced session can be modified by simply announcing the modified
>session description.  In this case, the version hash in the SAP header MUST
>be changed

There is no field called the 'version hash' - there is a 'version' 3-bit
and there is a 'msg id hash' - you want the latter, right?. Later in the
same paragraph it notes

>The session itself,
>as distinct from the session announcement, is uniquely identified by the
>payload and not by the message identifier hash in the header.

so that seems to confirm its use.

Cheers,
	Markus

Markus Buchhorn,  Advanced Computational Systems CRC     | Ph: +61 2 62798810
email: [email-masked], snail: ACSys, RSISE Bldg,|Fax: +61 2 62798602
Australian National University, Canberra 0200, Australia |Mobile: 0417 281429

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From: Ross Finlayson <[email-masked]>
Date: Thu, 06 Jul 2000 21:47:36 -0700

>mstar stuff, but no others.

My "liveCaster" application - <http://www.live.com/liveCaster/> - also 
sends out SAP announcements, when run in "audio" mode (to stream MP3 
files).  So this is another program that you can use for testing.

>  (At the same time what listeners are there? I'm also

There's also "multikit" - <http://wwe.live.com/multikit/>.  (To get SAP 
announcements, open the "SDP default" directory.)

         Ross.

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From: Pieter Liefooghe <[email-masked]>
Date: Fri, 07 Jul 2000 11:18:51 +0200

> writing a sap announcer, so need somebody else to check against.)

Hi,

I've implemented a Session Directory tool for Windows called CastGuide and is
available at: http://www.castguide.com/

The version available on the website is only SAPv1 compliant. It has the same
functionality as the (Unix) SDR tool but does in addition support Multikit like
directories and compressed announcements like the ones made by RealServers when
their SAP/SDP packet is larger then 1K, together with many other nifty features
;-)

In the version I'm currently working on I support SAPv2 (spec 06) with
Authentication and Encryption. This version should be released within a few
weeks.

> (and also not set it to zero as they "SHOULD" not)?

In the version I'm implementing I strictly follow the spec...or at least I try
;-)

> and there is a 'msg id hash' - you want the latter, right?. Later in the

That is how I implemented it.

> so that seems to confirm its use.

indeed.

Bye,

Pieter
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pieter Liefooghe
Research Assistant
Vrije Universiteit Brussel (INFO/TW)
Digital Telecom Dept.
Pleinlaan 2
1050 Brussel
BELGIUM
Tel: +32-2-629.29.77
Fax: +32-2-629.28.70
[email-masked]
http://infoweb.vub.ac.be/~pliefoog

Quote of the day:

Any program that runs right is obsolete.