Re: [Asterisk-Users] Silence suppression on SIP calls generated from Asterisk?

2004-04-05 Thread Olle E. Johansson
Brian Cuthie wrote:
Let's say that I have a call coming in to Asterisk through a TDM400P and 
going out through SIP to someone on the Internet. Is there any 
configuration option that would allow me to do silence suppression on 
the RTP stream generated by Asterisk on behalf of the TDM400P connected 
user?  SIP phones allow me to do this easily, but I'd like to be able to 
conserve upstream bandwidth on calls that don't emanate from a SIP phone 
here at my location.
Asterisk SIP does not support silence suppression. In fact, using Silence
suppression on an inbound RTP stream will lead to problems, since Asterisk
takes timing from inbound RTP streams.
/Olle
___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users


RE: [Asterisk-Users] Silence suppression on SIP calls generated from Asterisk?

2004-04-05 Thread Brian Cuthie
 

 -Original Message-
 From: [EMAIL PROTECTED] 
 [mailto:[EMAIL PROTECTED] On Behalf Of 
 Olle E. Johansson
 
 Brian Cuthie wrote:
  
  Let's say that I have a call coming in to Asterisk through 
 a TDM400P 
  and going out through SIP to someone on the Internet. Is there any 
  configuration option that would allow me to do silence 
 suppression on 
  the RTP stream generated by Asterisk on behalf of the TDM400P 
  connected user?  SIP phones allow me to do this easily, but 
 I'd like 
  to be able to conserve upstream bandwidth on calls that 
 don't emanate 
  from a SIP phone here at my location.
 Asterisk SIP does not support silence suppression. In fact, 
 using Silence suppression on an inbound RTP stream will lead 
 to problems, since Asterisk takes timing from inbound RTP streams.
 

Yeah, funny thing is I saw this problem just last night while messing around
with music on hold. I had VAD on the SIP phone on and the MOH would stop
unless I talked. I thought it was quite weird when it happened; now it makes
sense. 

I've heard that Asterisk derives its timing in strange ways, but I've been
wondering why it doesn't use the machine's clock (real-time interrupt, not
wall-clock).

-brian 

___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


RE: [Asterisk-Users] Silence suppression on SIP calls generated from Asterisk?

2004-04-05 Thread John Todd
At 8:34 AM -0400 on 4/5/04, Brian Cuthie wrote:
  -Original Message-
  From: [EMAIL PROTECTED]
 [mailto:[EMAIL PROTECTED] On Behalf Of
 Olle E. Johansson
 Brian Cuthie wrote:
 
  Let's say that I have a call coming in to Asterisk through
 a TDM400P
  and going out through SIP to someone on the Internet. Is there any
  configuration option that would allow me to do silence
 suppression on
  the RTP stream generated by Asterisk on behalf of the TDM400P
  connected user?  SIP phones allow me to do this easily, but
 I'd like
  to be able to conserve upstream bandwidth on calls that
 don't emanate
  from a SIP phone here at my location.
 Asterisk SIP does not support silence suppression. In fact,
 using Silence suppression on an inbound RTP stream will lead
  to problems, since Asterisk takes timing from inbound RTP streams.

Yeah, funny thing is I saw this problem just last night while messing around
with music on hold. I had VAD on the SIP phone on and the MOH would stop
unless I talked. I thought it was quite weird when it happened; now it makes
sense.
I've heard that Asterisk derives its timing in strange ways, but I've been
wondering why it doesn't use the machine's clock (real-time interrupt, not
wall-clock).
-brian
Interestingly enough, Mark and I talked about this problem very 
briefly at dinner the other night.  My recollection is that he seemed 
to think that taking timing from a Zap driver would be feasible, but 
there were many other things to do ahead of time.  Perhaps others can 
program this or encourage it's development.

Personally, I think VAD is a great service, as well as comfort noise 
generation to disguise when VAD is working.  I'll always encourage 
methods that reduce bandwidth.   Most major developers on Asterisk 
consider these technologies of low concern since their bandwidth is 
unlimited, as they typically sit in a co-lo somewhere (as many 
programmers of * are providers of service, not consumers.)  The 
reality for most end users is that they are on very restricted pipes 
that are delivered via a WAN technology (especially for outbound, if 
you consider residential) and being able to put more customers into 
expensive bitstreams makes a lot of financial sense.

JT

___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users


Re: [Asterisk-Users] Silence suppression on SIP calls generated from Asterisk?

2004-04-05 Thread Olle E. Johansson

Personally, I think VAD is a great service, as well as comfort noise 
generation to disguise when VAD is working.  I'll always encourage 
methods that reduce bandwidth.   Most major developers on Asterisk 
consider these technologies of low concern since their bandwidth is 
unlimited, as they typically sit in a co-lo somewhere (as many 
programmers of * are providers of service, not consumers.)  The reality 
for most end users is that they are on very restricted pipes that are 
delivered via a WAN technology (especially for outbound, if you consider 
residential) and being able to put more customers into expensive 
bitstreams makes a lot of financial sense.
I agree fully. We need to implement a good timer in the SIP channel,
both for VAD (but that's really in RTP, isn't it?) and for general
SIP timers according to the RFC.
Last week I also learned that DSL in the US is not as fat as DSL
in general is over here. Anything below 384 upstream is nothing you
can sell in Sweden :-)
/O
___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users


[Asterisk-Users] Silence suppression on SIP calls generated from Asterisk?

2004-04-04 Thread Brian Cuthie
Title: Silence suppression on SIP calls generated from Asterisk?







Let's say that I have a call coming in to Asterisk through a TDM400P and going out through SIP to someone on the Internet. Is there any configuration option that would allow me to do silence suppression on the RTP stream generated by Asterisk on behalf of the TDM400P connected user? SIP phones allow me to do this easily, but I'd like to be able to conserve upstream bandwidth on calls that don't emanate from a SIP phone here at my location.

Thanks


-brian