Time Alignment timer value

Hello all,
If network does not configure the Time Alignment timer value, then what should be the default value?

Should be Infinity.

Is there any spec reference for this?
Because this is need and IE which specify no action.

In E///, it is infinity by default.
In Nokia, it was 10240 then infinity was introduced by latest SW releases.

Thanks.
Spec does not say anything on the default value.

It should be SF10240, (its good that uplink Time alignment tuner should be expire)
By setting this and enabling Timingadvcmdopt switch, you can improve CDR, (i have obtained significant gain on Top CDR cases)