Poor audio quality multicast paging with Grandstream GXP2130

Can anyone confirm successful multicast “page all” functionality with Grandstream GXP-2130 and GXP-2160 phones? I’m experiencing horrible audio quality that sounds like very rapid audio drop outs and renders the page unintelligible. I’m testing using only 2-3 phones connected to the network. Paging using page groups works fine and produces very clear audio but ultimately, I need to be able to page over 90 endpoints so regular page groups aren’t an option.

I’m currently using Asterisk 13.2.0 with FreePBX 12.0.51. I have posted on the FreePBX forums and received a couple of helpful suggestions including how to confirm that Asterisk is using the ulaw codec during multicast paging (it is) but I think that’s run its course. At this point it’s not clear whether this is a phone issue, a configuration issue, or something related to Asterisk and I’m hoping someone can help shed some light or has suggestions on how to best troubleshoot this.

Thanks – Steve

Stuttering audio tends to happen if the disk can’t be read fast enough. That is normally a problem associated with running on a virtual machine. Is that the case here?

FreePBX is installed on a dedicated box; Dell PowerEdge 2950 III with dual 2.6GHz QuadCores, 16GB of RAM and two 300GB SAS drives in a RAID 1 config.

We’re tested on other hardware and have the same issue. Sangoma support has also confirmed that they see/hear the same thing when they set up two Grandstream GXP-2160s. At this point it appears to be a phone issue. I have a support ticket open with Grandstream and they indicated they’ve not received any other reports of this problem but will look into it.

Sucks, because I’m sitting on 100 brand spankin’ new GXP-2130s and multicast paging is essentially unusable. We’re a special needs school and I need to be able to do “Page All” to 90+ phones.

I’m open to suggestions if anyone has any.

Has Asterisk been sending any media to the phone before the file? Asterisk doesn’t generate all the SSRC changes it should and some phones get confused as a result.

Sorry, not sure I follow. The pages are live not prerecorded messages. The FreePBX paging module has the ability to play a recording when the page is initiated. I have tried paging with this setting set to default (a short beep) and to none and the results are the same. I’ve also tried prerecorded pages and have the same horrible audio.