3Com 3C13840, Руководство по установке

Страница: 76 / 82

76 C
HAPTER
8: F
LEXIBLE
I
NTERFACE
C
ARDS
1-port OC-3 ATM MM should be connected with multi-mode optical fibers
whereas 1-port OC-3 ATM SM / 1-port OC-3 ATM SML should be connected with
single-mode optical fibers.
2-port ADSL (over
POTS) FIC (3C13872)
ADSL (Asymmetric Digital Subscriber’s Loop) interface card (2-port ADSL FIC)
provide the users with the telephone line-based ADSL access that allow a LAN
subscriber to reach the DSLAM (Digital Subscriber's Loop Access Multiplexer) of
the exchange office through a regular analog subscriber line, and then access the
ATM/IP backbone or Internet. Thus, high-speed data communications and Video
on Demand (VoD) can be fulfilled. As ADSL uses the High Frequency (HF) band
higher than 26 KHz for data transmission, its activities will not interfere the voice
service (which occupies the Low Frequency (LF) band in the range of 0 to 4 KHz)
implemented over the same line. Normally, the subscriber can be provided with a
speed in the range of 32 Kbps to 8 Mbps (downlink rate) and a speed in the range
of 32 Kbps to 1 Mbps (uplink rate).
ADSL interface cards:
■
Supportfor ADSL over POTS (Annex A)
■
Allow manual activation/deactivation of ADSL line, and support SAR loopback,
which facilitates fault isolation.
■
Support interface standards of G. DMT, G. Lite, and T1.413 and the
configuration of auto-sensing.
■
Support network lattice coding (except for G. Lite) on ADSL interfaces,
enhancing the stability of ADSL connections.
Interface Attributes
Table 16 2-port ADSL FIC interface attributes
Panel and Interface LED The following figure illustrates the FIC-1ADSL panel.
Attribute 2-port ADSL FIC
Connector RJ11
Interface number
1 (FIC-1ADSL)
2 (2-port ADSL FIC)
Interface speed
In ADSL Full Rate mode (i.e., ITU-T 992.1 G.DMT/ANSI
T1.413):
The downlink speed can reach 8160Kbps, and the uplink
speed can reach 896Kbps.
Interface standard
ITU-T 992.1 G.DMT (Annex A)
ITU-T 992.2 G.Lite
ANSI T1.413 Issue 2
Cable and the
max. transmission
distance
The ADSL interface cable is telephone cable.
In full rate, the transmission distance can be as far as 1.8 km,
or 6000 feet (the maximum transmission distance depends on
the line quality).
Supported service ADSL access over the telephone line