I am currently experiencing intermittent silences with my asterisk system. The symptoms are as follows: * Both for incoming and outgoing calls, I (and other users) occasionally experience a brief period of silence. * The silence lasts anywhere from 3 to 10 seconds. * It is not due to silence suppression, because the silences generally occur in the middle of sentences. * Silences occur at various times of the day, for calls of various lengths, and at different times during calls. * Sliences have occured for incoming and outgoing calls, and have affected both people on the VoIP side and the PSTN side. * Silences have occured for devices from multiple manufacturers (Currently we are using Polycom IP 300, IP 500, and Grandstream 101). * Affected users are connecting to our asterisk system from multiple geographic areas, using multiple ISPs, and all seem to have reliable and acceptable network connections. * All users are connecting to the asterisk system via SIP. * Multiple "carriers" have been used, and the issue seems to not be related to any particular carrier. * Call load doesn't appear to be an issue, as the silences have occured when the call in question was the only one on the system. The current asterisk system configuration is as follows: * 1.2 GHz Pentium Celeron 512 GB RAM, Linux 2.4.21 * 10 SIP devices connected * Connected to Carriers via IAX * Using uLaw codec * Using asterisk HEAD, built on June 28th * Running ztdummy * Server is not firewalled. I have tried, to no avail, to find a solution for this issue, and I am having no luck. The issue is perplexing, and quite bothersome to our users. Could anyone suggest any solutions, tests or anything? At this point, I'm getting frantic, and any help would be appreciated. Stuart
First, I would like to commend you on your excellent list post. Detailed without burying people in details and to the point, and not running around pointing fingers. Now for the bad news. On Wednesday 13 July 2005 15:40, Stuart Lester wrote:> I am currently experiencing intermittent silences with my asterisk system. > The symptoms are as follows:> * Both for incoming and outgoing calls, I (and other users) > occasionally experience a brief period of silence. > * The silence lasts anywhere from 3 to 10 seconds. > * It is not due to silence suppression, because the silences > generally occur in the middle of sentences. > * Silences occur at various times of the day, for calls of various > lengths, and at different times during calls. > * Sliences have occured for incoming and outgoing calls, and > have affected both people on the VoIP side and the PSTN side.I had more or less identical symptoms. I'd tried new motherboards, new cards, experimental code, you name it. We finally broke down and have made only one change to our setup, which I'll explain below.> * Affected users are connecting to our asterisk system from > multiple geographic areas, using multiple ISPs, and all seem to have > reliable and acceptable network connections.This tells me it is on your side. Our system looks like this: Norstar MICS [ PRI ] Asterisk 1 [ SDSL ] Asterisk 2 [ PRI ] Telco The SDSL loop is just a 4ish-km link between a downtown location and the office. It terminates into a regular old switch (Baystack 350) which also carries the internet traffic for a half dozen businesses. It is not VLANned or anything, and the traffic between Asterisk 1 and 2 is over RFC1918 addresses. Asterisk 2 can route calls through the telco PRI or through one of a half dozen VOIP providers. The change we made? We stopped routing calls over the VOIP providers. As soon as we did that our intermittent silent periods *disappeared*. We've been routing all calls through the telco for the last 45 days or so, and do about 25-35000 minutes a month, if I'm not mistaken. This ruled out: - Asterisk 1 & 2 (mobo, card, NIC, everything) - Asterisk jitter buffer code - the switch - the SDSL hardware (Megabit Modem 300S) and loop Our culprit appears to be either the router, the ADSL uplink modem (Sangoma S518) or the uplink itself. I'd like to get another link and do some testing. I'm almost 100% certain it's not the hardware or the router (linux). In fact, we have the link, I just need to get the time to do the testing. My guess is that it's the upstream provider (Ikano), but I can't rule out the others yet. I am sorry I don't have better news for you. I would suggest trying a couple different upstream providers (even just regular ADSL should be good for initial testing and it's not expensive to try a few... I'm looking for a more inexpensive T1 provider in my area. -A.
Almost sounds like you and I have the same problem.. please check out my message (I just sent to the list) and see if it rings any bells would you? Stuart Lester wrote:>I am currently experiencing intermittent silences with my asterisk system. >The symptoms are as follows: > * Both for incoming and outgoing calls, I (and other users) >occasionally experience a brief period of silence. > * The silence lasts anywhere from 3 to 10 seconds. > * It is not due to silence suppression, because the silences >generally occur in the middle of sentences. > * Silences occur at various times of the day, for calls of various >lengths, and at different times during calls. > * Sliences have occured for incoming and outgoing calls, and >have affected both people on the VoIP side and the PSTN side. > * Silences have occured for devices from multiple manufacturers >(Currently we are using Polycom IP 300, IP 500, and Grandstream 101). > * Affected users are connecting to our asterisk system from >multiple geographic areas, using multiple ISPs, and all seem to have >reliable and acceptable network connections. > * All users are connecting to the asterisk system via SIP. > * Multiple "carriers" have been used, and the issue seems to not >be related to any particular carrier. > * Call load doesn't appear to be an issue, as the silences have >occured when the call in question was the only one on the system. > >The current asterisk system configuration is as follows: > * 1.2 GHz Pentium Celeron 512 GB RAM, Linux 2.4.21 > * 10 SIP devices connected > * Connected to Carriers via IAX > * Using uLaw codec > * Using asterisk HEAD, built on June 28th > * Running ztdummy > * Server is not firewalled. > >I have tried, to no avail, to find a solution for this issue, and I am >having no luck. The issue is perplexing, and quite bothersome to our >users. Could anyone suggest any solutions, tests or anything? At this >point, I'm getting frantic, and any help would be appreciated. > >Stuart > >_______________________________________________ >Asterisk-Users mailing list >Asterisk-Users@lists.digium.com >http://lists.digium.com/mailman/listinfo/asterisk-users >To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > > >-------------- next part -------------- A non-text attachment was scrubbed... Name: mhess.vcf Type: text/x-vcard Size: 279 bytes Desc: not available Url : http://lists.digium.com/pipermail/asterisk-users/attachments/20050713/5571e44e/mhess.vcf