| Level | Feature | Support |
|---|
| basic |
| send INVITE over UDP |
Yes |
| receive INVITE over UDP |
Yes |
| generate ACK properly |
Yes |
| can accept or reject calls |
Yes |
| SDP with single m and c line, one codec |
Yes |
| To, From, Call-ID,
CSeq, Via, Content-Length,
Content-Type headers handled properly | Yes |
| generate tags in To field |
Yes |
| send basic call termination with BYE via UDP |
Yes |
| receive BYE over UDP |
Yes |
| compact form for headers |
Yes |
| reject unknown request methods with 501 response |
Yes |
| send/receive RTP media, possibly without RTCP |
Use external media application |
| intermediate |
| support TCP for all messages |
Yes |
| Require, Proxy-Require |
No |
| handle packet loss for INVITE and
BYE (with exponential backoff) | Yes |
| pays attention to Contact header in
INVITE and in 2xx response to INVITE (i.e., goes
directly to peer for following requests) | Yes |
| process CANCEL for INVITE |
Yes |
| Authentication for registrations: basic |
Yes |
| Authentication for registrations: digest |
Yes |
| allow redirection to web pages or email |
Yes |
| receive text or HTML in 3xx or 4xx responses |
No |
| Accept headers without SDP |
No |
| DNS SRV records | Yes |
| non-gateways: register with periodic refresh to
unicast address, paying attention to Expires header in
REGISTER response | Yes |
| understands redirection |
Yes |
| multiple codecs listed in SDP m line, finds
common one with peer | Yes |
| multiple SDP m= lines handled correctly |
Yes |
| unknown SDP m= media types handled
correctly (i.e., rejected with port 0) | Yes |
| Domain name as well as IP address accepted in SDP
c= line | Yes |
| generate RTCP packets |
Use external media application |
| respond to OPTIONS request |
Yes |
| allows non-SIP URLs in REGISTER |
Yes |
| copy Record-Route from response into
Route of request and route appropriately | Yes |
| checks equality of action parameters on
REGISTER | No |
| can retrieve current registrations |
Yes |
| can clear registrations with Contact: * and
Expires: 0 | Yes |
| advanced
|
| automatically tries redirections (recursing UA) |
Yes |
| generate multicast REGISTER |
No |
re-INVITE: suspending a stream |
Yes |
re-INVITE: resuming a stream |
Yes |
re-INVITE: closing single stream |
Yes |
re-INVITE: changing codecs |
No |
re-INVITE: add a stream |
Yes |
re-INVITE: change media address to
different address or port (mobility) | Yes |
| send text or HTML in 3xx and 4xx responses |
No |
Expires for INVITE |
No |
| third party registration |
Yes |
| generate tel: URL request and proxy
them to designated server | No |
| process MIME multipart responses |
Yes |
| beyond RFC3261 |
| Emergency call handling |
Yes |
| INFO method |
Yes |
| TRANSFER method |
Yes |
| 183 response |
No |
| caller preferences |
No |
| tones (DTMF) in RTP |
No |
| SIP for presence (SUBSCRIBE and NOTIFY method) |
Yes |
| SIP for instant message (MESSAGE method) |
Yes |
| SIP for device control (DO metod) |
Yes |
| Use MESSAGE method for web browsing sharing |
Yes |
| Send location information in MIME |
Yes |
| service engine |
| SIP CGI |
Yes |
| Language for End System Services (LESS) scripts |
Yes |
| Service creation environment |
Supports both graphical and web based |
| Service learning (Automatically generate service scripts) |
Yes |
| Feature interaction handling |
Yes |
| Others |
| Address book |
Yes |
| Session Announcement Protocol support |
Yes |
| Real Time Streaming Protocol support |
Yes |
| Service Location Protocol support |
Yes |
| Location sensing |
Yes |