I want to validate International mobile subscriber identity (IMSI) numbers. What is the valid range of IMSI numbers? Please let me know about specification or any web link.
I'm not sure this question has an answer, as this number is both highly dependent on each country's independent numbering plan .
The first 5 digits of the IMSI consists of an MCC (Mobile Country Code) + MNC (Mobile Network Code) combination of which, according to this site, there are 1663 entries as of 3/24/2016. These combinations are not sequential and were designed to accommodate natural population growth. So the sequences skip around somewhat arbitrarily mainly because they mostly are.
The remaining 10 digits are the MSIN (Mobile Subscriber Identification Number), which is basically a phone number. This number is regulated by each country's numbering plan, which vary considerably from country to country.
So, there's really no cohesive rule you can use to verify IMEI integrity, other than some sort of database lookup.
Wish you luck in your search and your project!