Running Asterisk 1.4.22-2
Aastra 480i phones
This problem didn’t exist for over 2 years with this setup and nothing has changed recently to trigger this event.
We have 3 offices and a datacenter connected by an MPLS, cisco switches and routers configured with QOS. All calls go through the MPLS and in or out through the PBX at a centralized datacenter, there is not a PBX in each office.
We get intermittent call quality issues where it is either very staticy or the audio simply drops. From most sources the audio issue is one way, ie they hear us we just don’t hear them. But this isnt confirmed in all cases of the issue. It can happen on inbound, outbound and interoffice calls in any office in the company. There is nothing common between the instances to pinpoint it to any specific problem thus far, it is very intermittent.
What I’ve done so far.
Tried different phones(still Aastra 480i’s) and headsets(various Plantronics models) with a user identified to have the call quality issue frequently. No benefit from switching any hardware on the user level.
Capture data from the PBX to a specific phone. Analyze the data with wireshark when the user notifies me of a call with the call quality issue. It plays back crystal clear in wireshark, no missing audio or staticy sound.
Installed a softphone and configured with above said users extension. Captured from the phone to the pbx, this capture took place over the course of over a full week(roughly 180-200 calls per day) and this call quality issue didnt happen once in this timeframe. The user would experience it multiple times per day with the Aastra phone.
At first glance it would seem to me that the problem is with the Aastra phones, but why it didn’t happen for over two years and now all of a sudden it does makes me question the problem. Thus my reason to come here.
I’ll post some configs as I’m not 100% sure of the validity of these since i was not the one who setup the PBX.
;Sangoma A104 port 1 [slot:1 bus:11 span:1]
;Sangoma A104 port 2 [slot:1 bus:11 span:2]
trunkgroup => 1,24,48
spanmap => 1,1,0
spanmap => 2,1,1
rxwink=300 ; Atlas seems to use long (250ms) winks
; Whether or not to do distinctive ring detection on FXO lines
;Include genzaptelconf configs
;Include AMP configs
#Sangoma A104 port 1 [slot:1 bus:11 span:1]
#Sangoma A104 port 2 [slot:1 bus:11 span:2]