| Ingress/Egress Field Information | Field | REGISTER | SUBSCRIBE / REFER /
NOTIFY | MESSAGE / PUBLISH /
OPTIONS | Field Length | of Each Field |
|---|
SIP Request URI Header 1 | 1 | X | X | X | 256 |
Call ID 2 | 2 | X | X | X | 256 |
From Header 3 | 3 | X | X | X | 256 |
To Header 4 | 4 | X | X | X | 256 |
Expires 5 | 5 | X | X | | 10 |
Contact Address in Request 6 | 6 | X | X | X | 128 |
Contact Address in Response
(Along with Feature Tag in Contact Header) 7 | 7 | X | X | X | 128 |
Accept-Contact Header 8 | 8 | X | X | X | 200 |
Proxy-Authorization/WWW-Authenticate header 9 | 9 | X | X | X | 128 |
NAPT Status of the SIP SG for Signaling 10 | 10 | X | X | X | 1 |
Inbound SMM Indicator 11 | 11 | X | X | X | 1 |
Outbound SMM Indicator 12 | 12 | X | X | X | 1 |
IP Address for FQDN calls 13 | 13 | X | X | X | 48 |
Transport Protocol 14 | 14 | X | X | X | 1 |
ICID 15 | 15 | X | X | X | 64 |
Generated Host 16 | 16 | X | X | X | 64 |
Originating IOI 17 | 17 | X | X | X | 64 |
Terminating IOI 18 | 18 | X | X | X | 64 |
Asserted-Identity Header 19 | 19 | | X | X | 256 |
P-Visited-Network-Id 20 | 20 | X | | | 256 |
P-Called-Party-Id 21 | 21 | | X | X | 128 |
P-Charging-Function-Address 22 | 22 | X | X | X | 1024 |
| Transit IOI List 23 | 23 | X | X | X | 320 |
| Feature-Caps header 24 | 24 | X | | | 300 |
| P-Access-network-Info | 25 | X | X | X | 256 |
| User-Agent | 26 | X | X | X | 50 |