H3C Technologies H3C MSR 50 - Manual (Page 725)

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E1 and T1 interfaces
E1 interface
An E1 interface is logically divided into timeslots (TSs) with TS16 being a signaling channel.
On E1 interfaces, you can create PRI groups or TS sets.
You can use an E1 interface as an ISDN PRI or CE1 interface:
1. As an ISDN PRI interface, the E1 interface adopts DSS1 or QSIG signaling. As TS0 is used to
transfer synchronization information and TS16 is used as a D channel to transfer signaling, you
can arbitrarily bind any timeslot other than TS0 and TS16 as a logical interface, which is
equivalent to an ISDN PRI interface.
2. As a CE1 interface with a signaling channel, the E1 interface can adopt R2 signaling, digital E&M
signaling, or digital LGS signaling.
When R2 signaling is adopted, every 32 timeslots form a primary frame (PCM30 for example),
where TS0 is used for frame synchronization, TS16 for digital line signaling, and other 30
timeslots for voice transmission. Every 16 primary frames form one multiframe. In each
multiframe, TS0 in even primary frames conveys frame alignment signal (FAS) and TS0 in odd
primary frames conveys non–FAS (NFAS) about link status information. NFAS provides control
signaling for primary rate multiplexing. In the first primary frame, frame 0, the high-order 4 bits
in TS16 convey multiframe FAS (MFAS) and the lower-order 4 bits convey non-multiframe FAS
(NMFAS). TS16 in each of other 15 primary frames conveys line status information for two
timeslots. For example, TS16 in frame 1 conveys the digital line signaling status of TS1 and TS17
while that in frame 2 conveys the digital line signaling status of TS2 and TS18, and so on.
When digital E&M signaling is adopted, the E1 interface functions as a digital E&M interface.
On the interface, timeslot division and functions are the same as those with R2 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 an E1 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.
The Web interface supports only the PRI trunk signaling.
T1 interface
A T1 interface can be physically divided into 24 timeslots numbered TS1 through TS24.
You can use a T1 interface as an ISDN PRI interface. The interface adopts DSS1 or QSIG signaling. On
the interface, except TS24 used as D channel for signaling, you can arbitrarily bundle other timeslots into
an interface logically equivalent to an ISDN PRI interface.
In addition to DSS1 and QSIG 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.
Like E1 voice interface cards, T1 voice interface cards also have the features of voice subscriber lines.
The Web interface supports only the PRI trunk signaling.