Behind the scenes: GSM Registration

I have been curious about what goes on while waiting for a device to register on a network. I can usually expect to wait at least 5-10 min for a new SIM to register for the first time, and it usually takes a good number of re registrations before it can register instantly upon start up. So what determines how long this takes? Is the device waiting for confirmation from the Carrier to connect? I am up in Canada working on KORE SIMs so my devices always end up connecting as roaming (+CREG: 0,5) - should I expect longer registration times than if I were connecting to a home network?

I am wondering if there is anything I can do to speed up this process. It can get really annoying when it takes a device half an hour to register even though the coverage is great

Our GSM registration time is generally within 12 seconds on a home network, little longer if roaming.

What module are you using, and what firmware version are loaded on it?

WMP100 with FW 7.46

I have noticed that my Telit devices seem to register quicker, so maybe it is a hardware thing