confused on SMS between GSM and CDMA

[ronin]

While using a GSM phone, I receive SMS from a CDMA handset. However, the number that sent me the SMS is not the person that sent it to me?

It looks something like this :

Sent: (date)
From: +(unknown number)

Then inside the actual message, the originating MSISDN appears.

Any clues as to why this unknown number appears?

[guruananth]

As per Reliance CDMA and Supreme court rule that doesnt allow any sender id as alpha numeric.so that ot only accepts mobile phone