An IS/WISPs growth is an evolution process. Below I list a growth roadmap you should be following:
ADSL ==> ADSL Bonded => Diginet (>2mbps) => Low cost shared Fibre (2mb to 15mb)=> Multiple low cost shared fibre (15mb to 60mbs) => 1:1 fibre to cloud ( 10mb to 50mb) => mega 1:1 fibre to cloud (50mb to 100mb)=> 100mb+ P2P to Data Center with international and local breakout from DC.
Reseller (you sell & install, provider bills client directly and give you comm) => Share White Labelled Cloud infrastructure with major provider Ã¨Wholesale (you setup your own switch, usually Asterisk, in your office and negotiate with one or multiple providers to terminate at wholesale) => Upgrade to Carrier switch ( more robust, accurate billing, Unified Comms)still wholesale => grow the carrier switch into VoIP transit. Fixed transit low rate => move the VoIP switch into a major DC, this goes alongside your P2P connection for broadband=> obtain an interconnect with Telkom => obtain interconnect with the other GSM and VoIP providers!!
Note, the interconnects will cost you quite a bit of money, technical resources and financial commitments (guarantees)!so you would look at that only if you’re billing R1m+ pm in airtime and your company is worth (arguably) R5m+ in credit worthiness.