Nortel BCM 3.7, Manual

Page: 148 / 1004

148 Defining trunk module types and settings
N0008589 3.3
Timing within networks
In most T1/E1 network configurations, you need one DTM or BRI configured as Primary to act as
a primary reference and obtain clocking from the network.
The only application where you might not have a DTM/BRI designated as a primary reference is in
a private DTM/BRI network where your Business Communications Manager system is connected
to other equipment using T1/E1/BRI interface(s) that require a clock source and your system had
been designated as the source of clocking for that private network.
• If the other switches are to be clocked to your Business Communications Manager system, all
your DTMs/BRIs should be designated as Timing Master.
• If your Business Communications Manager system has two DTMs, you cannot assign both
DTMs as primary reference or both DTMs as secondary reference.
You can have one Primary reference and one Secondary reference per system.
• A T1, PRI(T1), PRI(E1), or BRI can act as the clock source.
T1 interface parameters (region-specific)
The T1 parameters heading appears for module types that have been configured as T1 or PRI. It
allows you to define a number of settings that are dependent on your T1 service provider settings.
1 Click the keys beside Resources ,
Media Bay Modules
, Bus <number> , Modules on Bus,
and Module <number> .
2 Click on T1 Parameters .
3
Configure the T1 parameters according to the information in the following table.
Table 13 TI parameters
Attribute Value Description
CO fail TIA-547A or
TR62411 Select the carrier failure standard used by your T1 or PRI service
provider. Consult your T1 or PRI service provider for the proper
setting.
Interface levels ISDN or PSTN Define a loss plan setting. For more information, see “Interface
levels” on page 149 .
Framing ESF or SF Select the framing format used by your T1 or PRI service
provider: Extended Superframe (ESF) or Superframe (SF).
Contact your T1 or PRI service provider for the proper setting.
(SF or Superframe is sometimes known as D4.)
Internal CSU On or Off Turn the internal T1 channel service unit (CSU) on or off. For
more information, see
“Internal CSU” on page 149 .
CSU line build 0, 7.5, or 15 dB Set the gain level of the transmitted signal. This setting appears
only when the Internal CSU is set to On.