i summon one kim

TL;DR SIP appears to be broken in the Asterisk 1.6 packages released to address DSA-2550. I resorted to a hasty upgrade to Asterisk 1.8 from backports. (more…)

I upgraded to Asterisk 1.6 some time ago, but didn’t think anything was wrong until recently. Calls coming in from Callcentric didn’t work: I received no audio. Everything had been working fine with Asterisk 1.4. I don’t get many calls, so initially I dismissed this as a temporary problem. Calls from my other four carriers kept working fine.

After some research, I noticed the following settings suggested by Callcentric:

session-timers=refuse
session-expires=180
session-minse=90
session-refresher=uas

I’ve placed this in the [general] section of sip.conf, because calls from Callcentric arrive from multiple servers and the way Asterisk handles SRV records, only one of the servers ends up mapping into the per-carrier context at any given time. It doesn’t seem to have an adverse effect on calls from other carriers. (It is just turning off functionality new to 1.6, and setting some sensible defaults.)

Ekiga has a problem talking from behind a firewall, or maybe the problem is that both the firewall and Ekiga are trying to be too clever. I’m running siproxd on the firewall to transparently handle SIP connections. All the hardware phones and ATAs as well as X-Lite work well, but Ekiga fails to register.

The fix is controversial: I’m disabling STUN.

gconftool-2 -s /apps/ekiga/general/nat/stun_server --type=string

However, this means Ekiga won’t work from less “intelligent” networks anymore. Since I’m considering Ekiga for my laptop, this might be a problem. Maybe I should try X-Lite under Wine.

I reconfigured my Nokia E65 mobile phone to connect to my Asterisk PBX, so I can make and receive SIP calls instead of cellular calls when I’m at home or at the office. I already had the corresponding WLANs configured on the phone for web browsing, so I didn’t have to do that part now (and thus those settings are not documented here). (more…)

I spent some time with my parents about a month ago fine tuning the echo cancellation on our SIP phones. Today I got a chance to refresh my memory while connecting the phones of a friend to a CallWeaver PBX I had setup for him. Hopefully I have now collected in one place all the settings that were changed from the factory defaults. If you have a Linksys SPA3102 phone adapter or a Linksys SPA942 phone, you may find some useful hints in here. (more…)

I could have saved some time if I had read more user comments from the Google results for unlocking my Vonage-provided Cisco ATA-186 adapter. It appears Vonage doesn’t want to unlock your adapter even after you have stayed with them for ages, or even if you pay them for the unlocking service.

I found this quite surprising, as I’ve been a satisfied Vonage customer for many years. I only discontinued the service several months after moving to Finland, when it was clear I was not using it enough to justify the cost.

Based on my experience today, though, it seems the horror stories are quite true. (more…)