atcomsystems.ca/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems OS7400 and remote SMT-i3105 "No MGI Channels Available"

Good day,

We have an OfficeServ7400 and are receiving the dreaded “No MGI Channels Available” when making calls from remote SMT-i3105’s. Remote phones connect and register with the OfficeServ. However, “no MGI channels available” is displayed when making a call to/from the remote station.

Some months ago we added a second OSA card (to handle some additional SMT-i3105’s, all local) and upgrade the OfficeServ software to v4.70. At this time “No MGI Channels Available” began on the few remote phones we have. The installer claimed the problem was due to NAT issues in our Firewall. I’ve updated our NAT’s and rules as recommend by the installer, yet the problem still persist.

I’ve wireshark’ed and see the remote phone register on UDP 6000. However, I’m not seeing any traffic in the 30000/31000 range when making a call. FYI in DM 2.1.5 VoIP RTP options are set to:
MPS Service: Off
No MPG to MGI: On
SIP to SIP MGI: On

Here is a list of current NAT’s:
5003 TCP --> OfficeServ
5060 UDP --> OfficeServ
5090-5091 TCP --> OfficeServ
6000 TCP/UDP --> OfficeServ
6001-6002 TCP --> OfficeServSVMi
6100 TCP --> OfficeServ
8000-8001 TCP/UDP --> OfficeServ
9000 UDP --> OfficeServ
30000 – 30031 UDP --> OfficeServOSA1
30032 – 30063 UDP --> OfficeServSVMi
31000-31031 UDP --> OfficeServOSA2
35000 – 35127 --> OfficeServSVMi
40000 – 41031 --> OfficeServOSA1
41000 – 41031 --> OfficeServOSA2

I need to get this remote issue resolved for a new hire. Any help is GREATLY APPRECIATED!

Looks like some overlap from 41000 to 41031

Sorry that is a typo.

The last two lines should read:
40000 – 40031 --> OfficeServOSA1
41000 – 41031 --> OfficeServOSA2

Check to ensure you don't have BGM to the IP phones in 2.5.6

Even if you have no external music attached, people will accidently turn it on and tie up MGIs. I've had sites dead in the water because all the MGIs were in use for background music.

The SMT phones don't use ports 30000 ~ 30128 for audio. They use ports 9000 and 9001. Your sip company is the one that makes the connection on the 30k range for audio coming from them. Make sure that the new 16 channels for OAS MGI are in group 805 and make sure that the card is setup to do MGI. By default it is setup to act as Mobex.

VIBob - Thanks for the suggestion, but BGM is disabled for all devices (we don't use it in this environment).

Biztel - I have UDP 9000-9001 open and forwarding to the OS7400. Both OAS cards are set for MGI 16. Forgive my ignorance but I'm not sure what you mean by "Make sure that the new 16 channels for OAS MGI are in group 805". How do I check group 805?

A few updated notes. I've spent most of the day wiresharking on the WAN with the SMT-i3105 as well on the LAN side of our pfsense firewall. The only traffic I'm seeing passed back and forth is on port 6000. Anyone else running OS7400 behind a pfsense box?

NOTE: We do not have any SIP trunks in the system just POT's coming from the CO to a 16TRK.

Can anyone point me to an official list of Port Forwards/NAT's from Samsung? I thought there was on in the release notes of software revision 4.65 but I can't locate it on GSBN.

Many thanks in advance!

Here is a direct picture from the manual for a 7400. Since you have no sip lines disregard my wording for 805. So you don't have to worry there. I would suggest opening tcp/udp for all ports.

Thanks Biztel! Can you please confirm the destination of the port forwards?

6100 --> OS7400
6000 --> OS7400
5060 & 5061 --> OS7400
30000-30031 --> OAS
9000 & 9001 --> OS7400
5002 & 5003 --> OS7400
5090 --> OS7400
5100 & 5101 --> OS7400??? (haven't seen this one before)

Sorry it has taken me so long to reply to you on this. I have been sick. Yes that is correct on your forwarding though. The 9000 and 9001 are just on the phone side. They must be pointed to the IP of the phone.

Biztel - No worries on the delay. I hope you are feeling better ;-) I hope to find some time to work on this further tomorrow. I'll be sure and post back.

I ran some wireshark captures today on a local SMT-i3105 that works fine. I believe I now have a clearer understanding of how traffic is passed between the OS7400 and the stations.

I have a feeling my problem is with outgoing NAT's and RTP traffic. I ran out of time today but I'm thinking source ports are being randomized by my firewall.

I have a pfsense box in production but have been testing Untangle. Does anyone have a working config on either of these platforms?