Multitenancy SIP Trunks

Owned by Maarten Meijer
Jan 10, 2018
1 min read

To keep customers separate it is important to have correct SIP trunk configurations. Our system can handel trunks from many providers. However problems can arise when one SIP trunk provider uses no authentication or other seperate methods on their SIP trunks.

Example

Customer A wants a SIP trunk with Provider X (delivered on 95.211.37.75:5060 from 100.100.100.10:5060).

Customer B wants a SIP trunk from Provider X as well (delivered on 95.211.37.75:5060 from 100.100.100.10:5060)..

  • SIP trunk of customer A gets configured.

All is well and the SIP is functioning as requested.

  • SIP trunk of customer B gets configured.

SIP trunk of customer B doesn't work and received 403 forbidden on the trunks

The example in the textbox above is an example where the SIP trunk provider does not use:

  • Authentication on the SIP trunks

  • Different Port+IP combinations for SIP trunks

Solutions

Different port or IP

If both trunks run the same configuration, simply changing the delivery port can help identifying the trunk for the provider.

Result

  • Customer A gets 95.211.37.75:5060

  • Customer B gets 95.211.37.75:5061

SoftApp-distribution will provide a port+ip to connect on.

Authentication

When authentication is enabled, the trunk will authenticate on the first outbound INVITE or register periodically.

Result

  • Customer A uses username customera with password passworda to authenticate with the provider.

  • Customer B uses username customerb with password passwordb to authenticate with the provider.