Hello, We see some strange behavior with phone calls, we use Asterisk 1.8.3.3. SIP clients (all behind NAT at different locations, so not a single NAT solution is used): - x-lite - linksys pap2t - polycom kirk (multiple type numbers) - polycom (multiple type numbers, hardware phones) Our Asterisk servers stays in between (some calls are recorded). Asterisk is running on a physical server (no virtual server software) with "old" hardware (Xeon 3.2 GHz with hypertrading and 4GB RAM, mainly used for buffers). We use a MySQL backend (CDR records are stored in it and SIP users are stored in a MySQL database). We use a SIP provider with a trunk for outgoing and incoming calls, this is also an Asterisk server if I'm correct. We currently do around 1000 calls a week and max. do 10 calls at the same time. The Asterisk server is not behind a NAT. What could the reason be audio in 1 direction is dropping? (Normally from the Asterisk server to the mentioned SIP clients.) No clear information is in the logs (it is like the call ended normally) and not all calls are having problem (most not, but it happens to often for us to start using VoIP more at the moment). To test if it was the firewall we disabled the firewall on the Asterisk server and moved the Asterisk server before the other firewalls we have. What could the problem be? And even more important what could solve it (and/or explain it)? Kind regards, Mark Scholten
On Fri, 2011-05-27 at 10:31 +0200, Mark Scholten wrote:> Hello, > > We see some strange behavior with phone calls, we use Asterisk 1.8.3.3. > > SIP clients (all behind NAT at different locations, so not a single NAT > solution is used): > - x-lite > - linksys pap2t > - polycom kirk (multiple type numbers) > - polycom (multiple type numbers, hardware phones) > > Our Asterisk servers stays in between (some calls are recorded). Asterisk is > running on a physical server (no virtual server software) with "old" > hardware (Xeon 3.2 GHz with hypertrading and 4GB RAM, mainly used for > buffers). We use a MySQL backend (CDR records are stored in it and SIP users > are stored in a MySQL database). > > We use a SIP provider with a trunk for outgoing and incoming calls, this is > also an Asterisk server if I'm correct. We currently do around 1000 calls a > week and max. do 10 calls at the same time. The Asterisk server is not > behind a NAT. > > What could the reason be audio in 1 direction is dropping? (Normally from > the Asterisk server to the mentioned SIP clients.) No clear information is > in the logs (it is like the call ended normally) and not all calls are > having problem (most not, but it happens to often for us to start using VoIP > more at the moment). > > To test if it was the firewall we disabled the firewall on the Asterisk > server and moved the Asterisk server before the other firewalls we have. > > What could the problem be? And even more important what could solve it > (and/or explain it)? > > Kind regards, > > Mark Scholten >Hi Are the broadband connections to the target SIP extensions dedicated for VoIP or does any other traffic run over them? We tend to find that 80% of call quality issues are caused by the broadband connection. A good diagnostic tool to keep an eye on the broadband connections involved is smokeping http://oss.oetiker.ch/smokeping/ We find it an absolute godsend. -- Ishfaq Malik Software Developer PackNet Ltd Office: 0161 660 3062
On Fri, May 27, 2011 at 10:31:57AM +0200, Mark Scholten wrote:>What could the reason be audio in 1 direction is dropping? (Normally from >the Asterisk server to the mentioned SIP clients.) No clear information is >in the logs (it is like the call ended normally) and not all calls are >having problem (most not, but it happens to often for us to start using VoIP >more at the moment).While the most usual problem is packet filtering / NAT, this generally manifests as no audio at all in one direction, not a drop in mid-call. But it's possible that one of the intermediate transit providers is doing something "clever". (Disabling ping, as you mention in your later email, is often a good indicator of a company with insufficient Clue.) Are you in a position to tunnel the traffic over a VPN or similarly flat and unfilterable network link? (This might be a good idea anyway.) Roger