<s>
VaxTele	B-Protocol
SIP	I-Protocol
Server	I-Protocol
SDK	I-Protocol
(	O
Software	B-Application
Development	I-Application
Kit	I-Application
)	O
is	O
a	O
complete	O
development	O
toolkit	O
,	O
which	O
allows	O
software	O
vendors	O
and	O
Internet	B-Protocol
telephony	I-Protocol
service	I-Protocol
providers	I-Protocol
(	O
ITSP	B-Protocol
)	O
to	O
develop	O
SIP	O
Server	O
and	O
(	O
SIP	O
)	O
Session	B-Application
Initiation	I-Application
Protocol	I-Application
based	O
VoIP	O
systems	O
for	O
Microsoft	B-Application
Windows	I-Application
to	O
install	O
computer	O
to	O
computer	O
voice	O
chat	O
,	O
chat	O
rooms	O
,	O
IVR	O
systems	O
,	O
call	O
center	O
services	O
,	O
calling	O
card	O
services	O
,	O
dial/receive	O
computer	O
to	O
PSTN	O
(	O
Public	O
Switched	O
Telephone	O
Network	O
)	O
and	O
mobile	O
phone	O
calling	O
services	O
.	O
</s>
<s>
VaxTele	B-Protocol
SIP	I-Protocol
Server	I-Protocol
SDK	I-Protocol
supports	O
Component	B-Application
Object	I-Application
Model	I-Application
(	O
COM	O
)	O
based	O
technology	O
and	O
can	O
be	O
incorporated	O
in	O
any	O
Microsoft	O
Windows-based	O
application	O
.	O
</s>
<s>
VaxTele	O
SIP	O
SDK	O
,	O
allows	O
to	O
add	O
many	O
IP-PBX	O
(	O
Private	B-Device
Branch	I-Device
Exchange	I-Device
)	O
related	O
features	O
:	O
voice	O
mail	O
,	O
call	O
transfer	O
,	O
chat	O
rooms	O
,	O
Interactive	O
Voice	O
Responses	O
(	O
IVR	O
)	O
,	O
multi	O
user	O
conference	O
call	O
,	O
auto	O
call	O
distribution	O
,	O
call	O
queues	O
and	O
stealth	O
listening	O
.	O
</s>
<s>
Some	O
of	O
them	O
are	O
Cisco	O
,	O
Linksys	O
,	O
Dlink	B-General_Concept
and	O
Quintum	O
.	O
</s>
<s>
There	O
are	O
many	O
Internet	B-Protocol
Telephony	I-Protocol
Service	I-Protocol
Providers	I-Protocol
(	O
ITSP	B-Protocol
)	O
are	O
available	O
on	O
the	O
internet	O
,	O
who	O
already	O
provide	O
service	O
to	O
dial	O
and	O
receive	O
SIP	O
based	O
phone	O
calls	O
to	O
and	O
from	O
PSTN	O
and	O
mobile	O
networks	O
.	O
</s>
