Subject: SAP/SDP-draft questions and comments

From: Peter Parnes <[email-masked]>
Date: Sun, 25 Aug 1996 16:33:46 +0200

Hi

* Explicit timeout question
According to draft-ietf-mmusic-sap-00 - draft 0.2:

page2)
Implicit Timeout should be done if we don't hear a announcement for more that 
10 times the announcement period or a minimum of 30 minutes. 

page7)
This page shows how to calculate the "base announcement interval" as interval 
= (8*no_of_ads*ad_size)/limit. It also says "It is also important to keep 
monitering other announcements and adjust the base interval accordingly."

My question is now: What is the _correct_ way to calculate the announcement 
period (for time-outs) for a client that is only listening? 
Should the client use some medium value of all sessions-announcements as the 
ad_size-value? 

* Missing type-letters 
draft-ietf-mmusic-sdp-02

The table on page 6 and Appendix A doesn't contain the types 'r' and 'z' that 
are mentioned on page 10 and 11.

/P

---

From: Mark Handley <[email-masked]>
Date: Sun, 25 Aug 96 17:04:22 +0100

>Should the client use some medium value of all sessions-announcements as the 

What I had in mind was that the client knows the size of the ad it's
thinking of timing out (it must have heard it to be able to time it
out), so it uses that value.

Perhaps I should make this more clear.

>are mentioned on page 10 and 11.

Thanks, I'll correct it.

Mark

---

From: Peter Parnes <[email-masked]>
Date: Sun, 25 Aug 1996 18:16:36 +0200

> out), so it uses that value. 

Ahh, yes of course (stupid me :-) but which bandwidth-limit should be used if 
you receive the ad on the non-scoped sap.mcast.net? I don't know which ttl the 
ad has been sent with, right? 

/P

---

From: Mark Handley <[email-masked]>
Date: Sun, 25 Aug 96 17:23:51 +0100

>ad has been sent with, right? 

If it's not encrypted, simply take the smallest ttl from the session
description - if the sender was playing by the rules, it shouldn't be
telling you about anything you can't receive.

If it's encrypted, you can't tell.  I guess you must assume the
largest possible ttl, but as you won't be displaying it unless you got
the appropriate key, it matters little anyway.

Mark