Aastra Dialog 4422 IP Office, User Manual

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123 MD Evolution – Dialog 4422 IP Office
QSIG-MD Private Network Services
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.