Sip show peer status not updated rapidly?

Hello every one i am using Asterisk Server 1.8 for my Android (2.3/4.0.3) phones…When any android phone is disconnected its status is updated after one minute in sip show peer [extension] command why ? is there any solution for this problem ?? because status is not updated when we disconnect any android phone from SIP, dial the number of disconnected android from other android handset it always rings. If i dial the same number after one minute then it indicates no response…

I am using native android SIP client…

Check or edit the qualify value to fit your needs.

You asked how to fix a problem before having identified a problem.

If you want the phones to become unavailable immediately, you will have to configure the phones to de-register themselves. That may mean using a different soft phone, which may not yet exist.

The phone will appear offline as the result of either re-registration timing out or the qualify test timing out.