Product analysis: innovaphone VoIP products 2010
Copyright © 2010 by ComConsult Technologie Information GmbH
Page 5
On a positive note, the firmware makes both
protocols available without needing extra
flash. Every device can thus use SIP and
H.323 at the same time. Multiple registration
makes it possible to register to both a H.323
gatekeeper and a SIP registrar to use both
services.
Using the SIP protocol, the telephone sys-
tems operate as B2BUA (Back to Back User
Agent) and thus terminate the signalling path
for the SIP terminals concerned. In contrast,
the RTP media stream is directly exchanged
between the end points for both SIP and
H.323. So-called “private networks” are an
exception: The PBX can be used as an RTP
relay if private networks are configured (Con-
figuration
→
IP
→
Settings). This makes it
possible to avoid NAT difficulties for the me-
dia stream.
SIP over TCP and TLS, SRTP in SIP and
H.323 have been supported since software
version 7.
QSIG support
Interconnecting PBXs is also enabled using
the ETSI standard QSIG. To do this, an IP
PBX, e.g. IP800, is connected via ISDN to
the existing PBX at both ends of the private
network. An existing IP connection is used
to establish the link between these two sys-
tems. The proprietary protocol used on the
PBX side (e.g. CorNet, NQ) and the corres-
ponding features are then tunnelled via QSIG
and finally transmitted to the respective party
(see Figure 5).
Open interfaces
In addition to Microsoft‘s traditional “Teleph-
ony API” (TAPI) for CTI applications and the
ISDN interface CAPI for fax, voicemail and
unified messaging (UM), there is also a SOAP
interface for individual adjustments and ex-
tensions. This enables simple integration of
IT and TC, enabling implementation of any
TC applications. Simple applications can be
implemented without delay, such as activating
a call diversion over a web site or displaying
customer data for an in-coming call.
In contrast, CSTA according to TR/84 is not
supported. An additional 3rd party gateway
e.g. from ESTOS is needed if the other party
requires CSTA (like Microsoft OCS does).
Selecting a telephone directory is organised
flexibly. Either the local PBX directory or an
external LDAP compatible directory can be in-
tegrated. Each directory can be activated or
deactivated independently.
ENUM
All models support the ENUM protocol, which
ensures ITU-T E.164- addresses are conver-
ted to a suitable IETF URI. Calls take place
over the IP connection if the subscriber has
stored a SIP-URI under his extension number,
instead of over the public telephone network
(which is usually more expensive).
The Austrian domain registration company,
nic.at, is a pioneer concerning ENUM, and
uses innovaphone PBXs in its offices in Vi-
enna and Salzburg. They use, for example,
Figure 5: System connection via QSIG
