Mitel MiVOICE BUSINESS, Инструкция по инженерии

Страница: 285 / 381

Network Configuration Specifics
271
• The default Fax transmission speed for Inter-zone Faxes is 7200 bps, this speed was
chosen so that the bandwidth requirements will be similar to the bandwidth requirements
for a G.729 voice call which would typically be used across a bandwidth constrained in-
ter-zone link.
• All other fields can be modified except for the "Label" field.
INTRA-ZONE DEFAULT PROFILE
• This profile determines how Faxes will be handled when transmitted between devices that
are located in the same zone.
• The Intra-zone Fax profile uses a default Fax profile setting of "1".
• A Fax profile setting of "1" causes Faxes to be handled as G.711 Pass Through
OTHER INTRA-ZONE PROFILES
• If a Fax profile other than "1" has been selected the Fax will be transmitted via T.38.
• The Administrator can create customized Fax profiles from "2" to "63".
• Each Fax profile can have a unique configuration.
RECOMMENDED SETTINGS
• Generally, a Fax transmission speed of 14,400 bps should be selected; however, the Ad-
ministrator may want to select a slower speed if there are bandwidth constraints.
• Fax transmissions are comprised of two different portions or phases, a low speed phase
(300 baud) that the Fax machines use to learn about each other's capabilities, and a high
speed phase (14,400 baud) that the fax machines use to transmit the actual Fax data.
• Mitel's T.38 solution uses UDP to transport ethernet packets. UDP does not have the ability
to re-send packets if packets are lost, so packet redundancy is supported. This allows the
Administrator to select the level of redundancy required for both the high speed and low
speed portions of a fax call.
• The 3300 ICP uses a redundancy default value of 3 for the low speed portion of the Fax
call, and 1 for the high speed portion.
• In ESM, if a redundancy level of 0 is selected, there will be no redundant packets transmitted
by the 3300 ICP, only the original packet will be transmitted. If a redundancy level of 3 is
selected, then the 3300 ICP will transmit the original packet and three redundant copies of
this packet.
• For most applications, the default values of 3 for the low speed portion of the Fax call and
1 for the high speed portion should be fine.
• Error Correction Mode (ECM) should be enabled if this capability is supported and enabled
on both Fax machines.
• Non Standard Facilities (NSF) capabilities. Whether or not to enable this capability requires
experimentation.