The SBC supports this feature over the SBC-GW-GW-SBC scenario.
The handling of History-Info, Diversion, and Identity headers by the SBC is enhanced, as described below:
The SBC filters out the History-Info headers added by network elements. It identifies such headers by the absence of the "user-info
" part. For example, the SBC ignores "History-Info: <sip:proxy1.example.com>;index=1
".
If Identity headers are present in the ingress INVITE to the PSX, the SBC sends a maximum of ten Identity headers to the PSX. The order of preference is as follows:
Request - Preference for Header Inclusion
Preference | Headers | Maximum Count |
---|---|---|
1 | Shaken identity header, if present in the ingress INVITE | 1 |
2 | Rest of the Identity headers from the ingress INVITE, if present | 9 |
For response, the order of preference for the inclusion of the headers are as follows:
Response - Preference for Header Inclusion
Preference | Headers | Maximum Count |
---|---|---|
1 | Shaken identity header (if present in the ingress INVITE), or an STI signed header | 1 |
2 | Newly signed DIV identity headers | 5 |
3 | Rest of the Identity headers from the ingress INVITE, if present | 4 |