| Product |
Basic
Interoperability |
Advanced
Interoperability |
| SIP
user agents |
UA-to-UA direct call,
no proxy server
UA-to-UA, through SIP
proxy server
UA-to-analog-phone,
through SIP proxy server |
Call
transfer |
Conference
calling |
Call
forwarding |
| Cisco
ATA-186 telephony adapter |
   |
 |
 |
 |
| Cisco
7960 SIP phone |
   |
 |
 |
 |
| Difinium
Mercury |
   |
 |
 |
 |
| Indigo
Software SIP User Agent |
   |
 |
 |
 |
| Mediatrix
APA III-4FXS |
   |
 |
 |
 |
| CyberTel
CyberCom Server Class |
   |
 |
 |
 |
| SIP
proxy servers |
UA-to-UA, through reference
SIP proxy server
UA-to-UA, through multiple
SIP proxy servers
UA-to-analog phone, through
SIP-based PSTN gateways |
Transport
negotiation |
Sequential
forking |
Parallel
forking |
Loop
detection |
| Indigo
Proxy Server |
   |
 |
 |
 |
 |
| Mockingbird
SIP server |
   |
 |
 |
 |
 |
| NetCentrix
call control server |
   |
 |
 |
 |
 |
| SS8
Signaling Switch |
   |
 |
 |
 |
 |
| Vovida.org
Vocal |
   |
 |
 |
 |
 |
| SIP-to-PSTN
gateways |
UA-to-analog phone, through SIP proxy server
SIP/IP trunking, analog phone through PSTN gateways
PRI trunking, UA to UA through PSTN gateways |
Codec
negotiation |
Transport
negotiation
(TCP-UDP) |
Fax
support |
Reinvite
method support |
| Cisco
AS5350 Universal Gateway |
   |
 |
 |
 |
 |
| Mediatrix
APA III-4FXO |
   |
 |
 |
 |
 |
| Mockingbird
Nuvostream multiprotocol server |
   |
 |
 |
 |
 |
| Nuera
ORCA GX-8 |
   |
 |
 |
 |
 |
Key Successful
interoperability
Not tested Not
supported |