HT8xx - packet size needs to be reduced

[SweetAction]

Hi 3CX Team,
Can you please update the template for the Grandstream HT8xx devices?

Currently the template sets a bunch of codes, which causes the packet from the ATA to exceed 1500 and fragment. 3CX doesn't handle fragmented packets at all and simply discards them.

Related threads:
3CX Forum:
https://www.3cx.com/community/threads/fxs-using-stun.63331/post-277059

Grandstream Forum:
https://forums.grandstream.com/t/in...m-2601-ip-phone-when-connected-with-3cx/52129

Grandstream Support Ticket:


3CX System: v18u5
Grandstream HT801 Firmware version: 1.0.41.5

By default, using the default options the grandstream HT801 cannot make calls (packet size is 1551, fragments at 1480). Simply changing the codecs in the WebUI reduces it enough to make calls, but obviously the template will keep setting it back and needs to be updated.

 

[JohnS_3CX]

Hi,

Quickly testing this on an SBC (HT802 - same but 2 FXS ports), I don't see such a large packet size on the invite, and the calls do work:


Not quite sure how you ended up with suck a large packet. Can you give some more details on this?

 

[SweetAction]

Just grabbed a new ATA and tested - here the packet got to 1514, but still fragmented:


The ata is 10.10.x.x and the PBX is 10.20.x.x

The re-assembled packet:


Showing all the codes being sent: