Features Of E1/T1 - 3Com MSR 50 Series Configuration Manual

■
n
■
■
T1 interface
A T1 interface can be physically divided into 24 timeslots numbered TS1 through
TS24.
You may use a T1 interface as an ISDN PRI interface. The interface adopts DSS1 or
Q.SIG signaling. On the interface, except TS24 used as D channel for signaling,
you may arbitrarily bundle other timeslots into an interface logically equivalent to
an ISDN PRI interface.
In addition to DSS1 and Q.SIG signaling, T1 interfaces support R2 signaling, digital
E&M signaling, and LGS signaling. Configured with digital E&M signaling, a T1
interface is used as a digital E&M interface; with digital LGS signaling, a digital
FXO or FXS interface.
n
■
■

Features of E1/T1

In addition to basic VoIP functions, E1/T1 voice is available with the following
features.
This section covers these topics:
■
■
■
Signaling modes
E1/T1 interfaces support these types of signaling:
■
■
When digital LGS signaling is adopted, the E1 interface functions as a digital
FXO or FXS interface. On the interface, timeslot division and functions are the
same as those with R2 signaling.
After you create a TS set and configure signaling on a VE1 voice interface card,
the system can automatically create the voice subscriber line for the TS set.
After TSs of an E1 interface are bound to form a PRI group, the system will
automatically generate the corresponding voice subscriber line.
Like VE1 voice interface cards, VT1 voice interface cards also have the
properties of voice subscriber lines.
When working in SF frame mode, T1 does not support R2, digital E&M or
digital LGS signaling.
"Signaling modes" on page 2311
"Fax function" on page 2312
"Protocols and standards" on page 2312
DSS1/Q.SIG user signaling, adopted on the D channel between ISDN user and
network interface (UNI). It comprises a data link layer protocol and a Layer 3
protocol used for basic call control.
ITU-T R2 signaling, which falls into digital line signaling and interregister
signaling. Digital line signaling is transmitted in TS16 (ABCD bits) of E1 trunk. It
conveys status information about E1 trunks to describe whether the trunks are
occupied, released, or blocked. Interregister signaling conveys information
about address, language and discriminating digits for internal calls, echo
suppressor, caller properties and callee properties in multi-frequency compelled
approach (forward and backward) in each timeslot.
Introduction to E1 and T1 2311