Failure of IAD Users to Register with the SoftCo

Publication Date:  2015-07-16 Views:  143 Downloads:  0
Issue Description
One SoftCo9500 is connected to 23 IADs. When internal users place calls to external users through the PRA trunk, frequent disconnections occur on customer's network and a registration failure is found on the IAD. However, the fault is automatically rectified in 10 seconds.
Handling Process
Diagnosis Flow:

1. Test the network between IAD and SoftCo.
No packets are lost.

2. Capture network packets.
Network packets carry IAD registration messages, but the SoftCo9500 does not respond. Run the following commands to check the traffic limitation data:
[%SoftCo9500(config)]$fpga show limitflux status
the max flux of SIP (packages/s): 0x7d0
By default, the SoftCo9500 can process a maximum of 125 SIP registration packages within a certain period. The customer has over 1500 SIP users. When more than 125 SIP users send registration requests to the SoftCo9500 at the same time, the SoftCo9500 discards some of the SIP packets, leading to call disconnections.


Step 1 Run the fpga set limitflux enable protocol sipreg flux 50 command to set the maximum number of registrations supported by the SoftCo within a certain period.

Step 2 Run the TERMINAL(config)#sip server 0 address expire-time 200 command to set the IAD registration time.

Root Cause
1.  The network is faulty, leading to packet loss and call disconnections.

2.  The SoftCo cannot process concurrent registrations at the same time, leading to call disconnections.
When IAD disconnections occur on the network and the IAD automatically recovers from the fault, users are advised to verify that the network is normal and registration packets are not discarded by the SoftCo.