registration caching missing

I have configured a surrogate agent on behalf of my IP-PBX to register to  Carrier.

last week ,i can get the registration caching through type "show sipd endpoint-ip xxxx" as surrogate agent register to the carrier constantly.

however, there is no registration caching about the same account"xxxx" though  surrogate agent register to the carrier continually and  the Carrier response a "200ok".

so ,how can i get the registration caching again?

thanks.