Hello,
Looking for SIP -> Whatsapp call gateway, it should take the calls from SIP (Freeswitch/Asterisk) and terminate to whatsapp number. Status of number should also monitored on whatsapp that means, if number is active on whatsapp, furthermore if it's getting the rings or not. It should also return the correct call error codes CALL SUCCESS, BUSY, UNAVAILABLE, etc.
We are a SIP operator. We have been in the Spanish telephone services market for 16 years, with our own developments using both Asterisk and Freeswitch.
Although some details need to be clarified that are not clear in the job description, we are sure that we can do what they require.