A certain carrier adopts Huawei MA5616. Subscribers reports that the fax service is abnormal (the fax data cannot be transmitted or received normally). The version of the MA5616 is MA5616V800R306C01B031.
The fax service data cannot be transmitted or received normally because a fault occurs.
1. Because the subscriber is migrated from the switch to the optical access device, it can be determined that the fault is not caused by the user fax machine.
2. Ping the signaling gateway. It is found that no packet loss occurs.
3. Check the data configurations of the fax machine and the softswitch. It is found that the parameters match each other, as shown in the following.
FAX transfers mode :Thoroughly
T38 Fax Port :RTP port
FAX flow :V3 Flow
4. Run the display fax-modem command. It is found that the MA5616 supports RFC 2198. Then, it is suspected that RFC 2198 is not enabled on the peer device. Capture signaling. It is then found that all services are normal from the start of fax flow to connection, but the fax service is interrupted during the negotiation of fax parameters. Then, it is determined that parameters are consistent. Disable RFC 2198 and the RFC 2198 and then test the fax service again. It is found that the fax service becomes normal. The fault is rectified.
1. The fax machine is faulty.
2. The line is faulty.
3. The fax mode of the MA5616 is different from the fax mode of the softswitch.
4. Certain parameters of the MA5616 mismatch those of the softswitch.
On Huawei MA5616, the RFC 2198 function is enabled by default.
RFC 2198 improves the reliability of data transmission through redundant transmission. When the network quality is poor, redundant transmission can ensure the service quality.