AASTRA 4223 Professional for MD Evolution User Guide - Manual (Page 142)

QSIG-MD Private Network Services
MD Evolution – Dialog 4223 Professional
142
QSIG-MD Private Network Services
Depending on the configuration of your telephone system, this
may be integrated within a QSIG-MD private network, which
groups various MD Evolution systems within your company.
These systems may be connected by:
•
Digital tie lines to a telecommunications operator. These digital tie
lines are therefore reserved for private calls within your company’s
network.
• Your company’s Intranet network, local area network (LAN), or
wide area network (WAN). In this case private telephone calls
between network calls are transmitted over the IP network, at the
same time as data that is exchanged between your company’s
various sites.
In the second case, there are two possible techniques:
•
The first, called IP-Trunking, uses proprietary messages that
are exchanged over the IP network. This applies when up to
7 MD Evolution systems are networked.
• The second technique, called IP-Networking, uses standardised
IP H.323 messages that are exchanged over the IP network.
This applies for a wide area network, which may include more
than 100 MD Evolution systems.
No matter the case and regardless of the private call supports used
within your company’s private network, the majority of the
telephone services available locally between two of your facility’s
internal users become available to the private users connected
through remote nodes.
Moreover, if IP-Trunking networking occurs over an IP network,
a non-IP hand-over service is also available for occasions where
there may be a downgrade in the voice transmission over the IP
network.