Telecom Question:
Explain gsm call flow for MS to SMS? and GSM call flow fro MS to roaming MS?

Answer:
First SMS is submitted to SMSC. than it is forwarded from
there to SMS gateway. SMS Gateway retrrives Routing info
from HLR and send it to MSC. MSC gets current location from
VLR of receipent mobile and delivers Msg.
there to SMS gateway. SMS Gateway retrrives Routing info
from HLR and send it to MSC. MSC gets current location from
VLR of receipent mobile and delivers Msg.