DP750 Problem with SIP over TCP missing ACK at 200 OK:

#1

Hi,

DP750 Problem with SIP over TCP missing ACK at 200 OK:

====> TRANSPORT TCP DP750 <====

All calls with TCP transport are cut in 32 seconds, in which it is observed that the 200 OK ACK is not received by the DP750.

Captures are attached:

  1. It can be observed in captura1_1.png the absence of the ACK (capture made on the DP750 itself).

wZUiTIr.png1316x423

  1. Detail of the INVITE in captura1_2.png.

TAjt7Uc.png814x490

====> TRANSPORT UDP DP750 <====

When the transport is configured in UDP, the calls do not fail, there is an ACK from the DP750.

Captures are attached:

  1. Captura2_1.png and Captura2_2.png

TAjt7Uc.png814x490

lMMDzg5.png1170x514

====> TRANSPORT TCP ATCOM <====

If I use another manufacturer brand, in this case ATCOM, the operation is correct:

Captures are attached:

  1. Captura3_1.png and Captura3_2.png

3JMVd87.png1298x183

vRwyw26.png896x450

Is this a bug in the SIP over TCP stack implementation on your DP750?
Or really, is there an option to define in the DP750 station, which I don’t see.

All the best,

#2

VoIP server?
Why are you using TCP instead of UDP?

#3

Hi,

Company conditions.
Asterisk 18.

Anyway, I don’t see why tcp shouldn’t work.

Regards,

#4

it was a question, then why it doesn’t work I can’t tell you, it could also be a voip server-side problem,
i were you if it works in udp, i wouldn’t try to do anything else.

Below the link to open a ticket for Grandstream support:

#5

Hi,

After further testing today, I have resolved the issue, I was at the provider’s layer 7 firewall where the PBX software is hosted, which blocked TCP/5060 requests to the public IP.

Regards,