For clients who make larger amounst of outbound calls, it might be necessary to use multiple Caller IDs, so in the case callee wants to call them back, calls are served by multiple recipients. For load balancing reasons the Caller IDs can be randomized, i.e. randomly selected from the pool. We have published a Step by Step guide how to set outbound calling with random caller ID.
Before setting it up, please be aware that Iin some jurisdictions it may be illegal to set Caller ID to the value of the number not assigned and/or belonging to you. Also it might be required that the number is reachable, i.e. answers when called back. Please check if this the case and proceed only if sure.
The guide gives a step by step explanation, but here we just touch the main concepts:
1. The Caller IDs are assigned from the DID numbers. I.e. we ensure that there are no Caller IDs assigned randomly, only from the pool available in the system. Moreover, the DIDs must be uploaded, assigned to the given client and enabled. This prevents from accidentally sending unwanted/unauthorized caller ID to the callee.
2. The method works regardless of the authentication type used for the account. That means not only individual SIP accounts, but also can serve larger clients, say PBXes authorized by Fixed IP address. The assignment of Caller IDs is transparent regardless of what method is used.
3. Since the Caller IDs are actually DID numbers, it is possible to set inbound calling with very little effort. Only thing needed, is to set the mapping of the DID towards local account or SIP URI.
You may also want to see: Caller ID based call rating and routing where we discuss how Caller ID can affetc rating and routing.
