Hello, guys!
Good day to you!
Today I will share with you how to deal with the problem that 3rd party device cannot call public IP terminal with H.323 protocol.
Description
The cisco and sony terminal register to SC failed with the H.323 protocol, caused the H.323 call fail.
Issue Description
The customer wants to register the 3rd party device such as cisco and sony terminal to SC with SIP and H.323 protocol.
The sip register successfully, but the H.323 register failed. Because there is a public IP terminal only provides the H.323 ID, so can't establish the call (use ID@IP method to call the public network terminal).
Handling Process
Firstly, the customer feedback the Huawei terminal can establish the call with the public terminal, but the third party device can't make a call.
So we checked the registration status and found the Huawei terminal register both SIP and H.323, but 3rd party only register with the SIP, then we remove the Huawei terminal H.323 registration, after that, Huawei terminal also can't call the public terminal, so means the public terminal only support H.323 protocol or the ID is just an H.323 ID, not SIP ID.
Then we confirmed the public terminal only supports H.323, so it's only a register problem so we collected the SC device log and Signaling diagnosis.
According to the Signaling diagnosis capture file, we didn’t found any register information in the capture file, so it's maybe a configuration problem when the add the terminal or the internal network problem. So we send the method to add unmanageable participants.
After changing the configuration and collect the Signaling diagnosis again, we can found the register message in the capture file and found the problem.
We checked the SC topology, and the SC only use one network port, and set an internal IP, then configure the NAT to a public IP, we collect the logs and found the when we reply the GCF message to 3rd party terminal, the address in the message is the SC NAT IP, not internal IP, so the 3rd party terminal sends the RRQ message to the NAT address, so the registration failed.
Root Cause
The call failed because the 3rd party H.323 register failed.
The no register message due to an error configuration when adding terminal is wrong.
The register failed because the IP address in GCF message is the NAT address, so the 3rd party terminal sends the RRQ message to the NAT IP, but that IP can’t get this message, so the register failed
Solution
For this situation, now there is no solution to register the terminal to SC use H.323 protocol, so we can only use other workaround plans:
Confirm if the public terminal support the sip call, and the sip ID, so that we can use sip protocol to call, this is the easiest way.
The way to call public without register: for Intranet terminal, dial SC Intranet ip##public terminal IP,e.g 0.0.0.0##1.1.1.1, and the public terminal call SC NAT IP## Intranet terminal IP e.g 2.2.2.2##3.3.3.3.
Now only use one network port and configure a NAT IP for the Intranet IP, and if using two network port, the one set the Intranet IP, and another set a public IP, the problem will not exist anymore.
Suggestions
Suggest use two network port;
And for the SC product, we need to improve to adapt more to vender's terminal in any scenario.
Thanks for reading!
