Impossible to register when you receive message 500

[samuelv@xxxxxxxxxxx (Samuel Vinson)]

Hi,

Thanks Benny to resolve the syntax error exception in message 500 
Registering glare condition.

But now I have a new problem. Schema 1 is normal process, and schema 2 
describes erroneous process. The last number is expiration delay.

1/ When I register my SIP account to server, the system uses two 
CALL-ID, because there is an IP address change detected. The normal 
exchange is presented below:

  client              server
     | register,id1,1800 |
     |------------------>|
     | 401,id1           |
     |<------------------|
     | register,id1,1800 |
     |------------------>|
     | 200,id1,1800      |
     |<------------------|
     |                   | IP address change detected
     |                   | Updating registration
     | register,id1,0    |
     |------------------>|
     | register,id2,1800 |
     |------------------>|
     | 401,id1           |
     |<------------------|
     | register,id1,0    |
     |------------------>|
     | 401,id2           |
     |<------------------|
     | register,id2,1800 |
     |------------------>|
     | 200,id1,0         |
     |<------------------|
     | 200,id2,1800      |
     |<------------------|

2/ Sometimes register step for id2 comes before unregister step for id1.
PjSip receive the error message 500, but it never retry after delay.
So the account is never registered :-(

  client              server
     | register,id1,1800 |
     |------------------>|
     | 401,id1           |
     |<------------------|
     | register,id1,1800 |
     |------------------>|
     | 200,id1,1800      |
     |<------------------|
     |                   | IP address change detected
     |                   | Updating registration
     | register,id1,0    |
     |------------------>|
     | register,id2,1800 |
     |------------------>|
     | 401,id1           |
     |<------------------|
     | register,id1,0    |
     |------------------>|
     | 401,id2           |
     |<------------------|
     | register,id2,1800 |
     |------------------>|
     | 500,id2           |500 Registering glare condition
     |                   |Already Pending Register
     |                   |Retry after 'delay'
     |<------------------|
     | 200,id1,0         |
     |<------------------|

- So I think there is bug when new call-id comes before unregister old 
call-id, isn't it ? Maybe, application should manage this situation and 
tries re-register after delay ?

- Why when IP address change detected you need to create a new call-id, 
and you can't use same with new ip ?

Thanks

Samuel