FreeSBC forwards incoming registration messages to the registrar but registrar returns an error

FreeSBC forwards incoming registration messages to the registrar but registrar returns an error. Please check the following points to solve this issue;

a. Check if SIP domain configured with correct registrar setting https://docs.telcobridges.com/tbwiki/Toolpack:Creating_a_SIP_Registrar_SBC_A

b. Check if Registrar NAP configured with a correct IP address https://docs.telcobridges.com/tbwiki/Toolpack:Allocating_a_SIP_Network_Access_Point_(NAP)_SBC_A
 
c. Check if your client configured with the correct username and password

d. Check the forwarding modes on FreeSBC, and select the correct one

Forwarding Modes

FreeSBC always modifies the contact URI in SIP register requests to remain on the path between SIP User Agents and registrars. FreeSBC supports two different SIP registration forwarding modes (i.e. "Contact Remapping" or "Contact Passthrough").
• The "Contact Passthrough" forwarding mode makes contact username portion of the contact URI in SIP register requests to pass through unchanged.
• The "Contact Remapping" forwarding mode modifies contact username portion of the contact URI in SIP register requests and makes it unique.

To check Forwarding modes; Go to SIP -> SIP Domains -> Select the SIP Domain Name -> Forwarding Parameters




e.  If your registrar wants to receive original headers from incoming requests, Forward the domain without any modification in From/To/Contact/P-Asserted-Identity SIP headers.  If you want to forward incoming SIP from/to header domain to outgoing leg you need to upgrade your FreeSBC to the minimum Release 3.0.114.  With Release 3.0.114 we added a forward_sip_domain script to our routing scripts.

This filter is used to forward the domain name (or IP address and port) from the incoming call to outgoing call, for the following SIP headers:

  - from (update call attribute :calling by appending :calling_sip_host and calling_sip_port)
  - to (update call attribute :called by appending :called_sip_host and called_sip_port)
  - P-asserted-identity (update call attribute :private_address by appending :private_address_sip_host and private_address_sip_port)

Installing this script:
  - This script is installed as a "route_remap" filter. In your main routing script, you need to add the following lines at appropriate places in the script:
  - require 'forward_sip_domain' unless defined?(ForwardSipDomain)
  - include ForwardSipDomain
  - route_remap :method => :forward_sip_domain
  - This script requires the routes to have a custom column named "forward_sip_domain", type boolean.
    (custom route column can be created in the "Routes" section of the web portal under "Create New Route Column")

Using this script:
In the WEB Portal, "forward_sip_domain" attribute is configured per route:
  - Under "Routes" section of the web portal (then under "Custom Parameters").

Please check the following wiki for more troubleshooting steps; FreeSBC Troubleshooting Guide