SIP Terminal Grandstream HT-502 problem on IPXoffice - Sundance Business VOIP Telephone Help

Hi,
I just hookup my Grandstream HT502 to my Tadiran IPXOffice.
This ATA box works fine between my other ATA Box(SPA2100). But when I call from HT-502 to any Tadiran phone (such as; T207M), I cannot hear anything but T207M hear my voice.
So my Grandstream works between ATA to ATA, but it's kind of oneway between ATA to T207M.
Do I need to change the default setting on HT502?
Please and appreciated for you help

regards.
Dendiko

Are the HT-502 and the T207M in the same zone?

How to check the zone on T207M?
My HT502 on zone 0 and I have another ATA SPA2100 also on zone 0 and can communicate without any problem to T207M.

Thanks

Are all the boxes on the same subnet?

No, the box on different subnet.
I have two location connected through Site to Site Tunel (VPN).
On the remote location which has HT502, also has some T207M. Those T207M works fine with central office except the HT502 box. The HT502 box only works good between other ATA Box in central office.
I set trusted network for the tunnel.
Is there anything else that I missed?

Thanks

I have an update,
I tested with X-Lite and I call out to any PSTN line but still not able to call internally to T207M (MGCP).
But I am surprise, I was able to called any internal T207M by calling my office PSTN line and go to internal extension which is T207M. So it works by calling from outside and goes to extension, but doesn't works if I call directly internal extension (voice only hear on one site).

Thanks
dendiko

I was under the assumption that SIP phone had to be on a separate zone than MGCP phones. Also, have you checked to make make absolutely sure you are not blocking any of the needed UDP ports? Wireshark is your friend and should be used to make sure. Usually one way voice is UDP blocking.

Thanks for the clue,
I just tested using Wireshark and doesn't works at the first until I found out that I have to use HUB instead of switch.
From the VOIP Call and RTP Stream capture, I found few interesting result on my IPX Office box.
1. Call MGCP(T207M) to MGCP(T207M) will take TCP 3932 and UDP 16400 (RTP)
2. MGCP to SIP(ATA186) will take TCP 5932 and UDP 16400
3. SIP to MGCP will take TCP 5932 and UDP 16400-16700, this UDP will keep change and going up until 16700 and back start from 16400 for any new SIP to MGCP call.
4. SIP to external call will forward to UGW(IPX Office second IP) and UDP 16400-16700(dynamicaly change)
5. Incoming call (from external) to SIP it will take TCP 5932 and 2 UDP ports between 16400-16700

I haven't check with my branch office, but at now I know what's going on during SIP call.

Thanks
Dendiko

MGCP AND SIP will take random source UDP port but the destination port should be 2427/5060 respectively.

SIP & MGCP can be on the same zone.

Thanks, but it still surprise me. Although my main office and branch is connected through VPN Tunel which is open on all port. I am still not able to make it works. I was wondering may be that's why tadiran also selling Sentinel gateway.
I think I gave up. I just feel I was choosing the wrong IPPBX and not too flexible such as Asterisk.
Tadiran support also doesn't help unless you buy Sentinel gateway.

The Sentinel isn't needed if on the same net. It is used as a proxy to translate external addresses to internal addresses. Especially if the phones are coming from the same external address. Sentinel will assign those different internal addresses so the UGW can sort out who is who. The 2427 (MGCP) and the 5060 (SIP) ports are control signaling. The Audio is in the RTP packets, 16400 thru 16700 for MGCP negotiated with SIP.

Sorry, meant to add. If the call is established, the control ports are working. If you then have one way audio, the RTP packet are not making it from one side to the other both ways, just one. Wireshark allows you to check up and down the line to see where they drop out.

Thanks Riman and Reataylor,
My main office and branch use Checkpoint Firewall on each site and connected through Site to Site VPN Tunel. Main office has internal IP 192.168.200.x and branch has 192.168.2.x . I just sending new ATA box (SPA2100) and I'll let you know also the wireshark data capture.