Справочник Пользователя для 3com SuperStack II
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Using WAN and
Serial Ports
Serial Ports
SuperStack II NETBuilder SI bridge/routers come with two or four serial
ports and one of the following WAN ports: a built-in ISDN S/T terminal
adapter (TA) (models 43x and 53x), a built-in ISDN U TA (models 44x and
54x), a built-in 56/64 Kbps CSU/DSU (models 45x and 55x) or a built-in
T1/FT1 Telco port (models 46x and 56x).
ports and one of the following WAN ports: a built-in ISDN S/T terminal
adapter (TA) (models 43x and 53x), a built-in ISDN U TA (models 44x and
54x), a built-in 56/64 Kbps CSU/DSU (models 45x and 55x) or a built-in
T1/FT1 Telco port (models 46x and 56x).
ISDN Port (Model 43x,
53x, 44x and 54x)
The ISDN port provides a basic rate interface (BRI). The BRI delivers two
bearer (B) channels and one delta (D) channel. Each B channel can
transmit up to 64 kilobits per second (kbps); the D channel transmits
information about the call to computers at the switching system at a rate
of 16 kbps. You can use both B channels together for a combined data
rate of 128 kbps, or use each 64 kbps B channel separately.
bearer (B) channels and one delta (D) channel. Each B channel can
transmit up to 64 kilobits per second (kbps); the D channel transmits
information about the call to computers at the switching system at a rate
of 16 kbps. You can use both B channels together for a combined data
rate of 128 kbps, or use each 64 kbps B channel separately.
Some ISDN lines support up to 56 Kbps per B channel. For more
information, contact your ISDN service provider.
information, contact your ISDN service provider.
Order ISDN lines from the phone company. See Appendix E for more
information about ordering ISDN lines.
information about ordering ISDN lines.
Installations in Hong Kong should be configured to originate and receive
ISDN calls at 64 Kbps. Due to the variety of ISDN switches in the Hong
Kong Telcom network, the SuperStack II NETBuilder SI bridge/router does
not handle rate adapted ISDN calls at 56 Kbps properly.
ISDN calls at 64 Kbps. Due to the variety of ISDN switches in the Hong
Kong Telcom network, the SuperStack II NETBuilder SI bridge/router does
not handle rate adapted ISDN calls at 56 Kbps properly.
56/64K CSU/DSU Port
(Model 45x
and 55x)
A CSU/DSU is equivalent to a modem for a digital line. The 56/64K
CSU/DSU port connects directly to a Digital Data Service (DDS).
CSU/DSU port connects directly to a Digital Data Service (DDS).
Order DDS lines from the phone company. Contact your phone company
for more information about DDS lines and the services available for them.
for more information about DDS lines and the services available for them.
T1/FT1 CSU/DSU Port
(Model 46x and 56x)
A CSU/DSU is equivalent to a modem for a digital line. The T1/FT1
CSU/DSU port connects directly to a T1 line or a fractional T1 line.
Fractional T1 consists of 24 channels (DS0s) at 64 Kbps each, so you can
connect to one or more DS0s with the T1/FT1 port.
CSU/DSU port connects directly to a T1 line or a fractional T1 line.
Fractional T1 consists of 24 channels (DS0s) at 64 Kbps each, so you can
connect to one or more DS0s with the T1/FT1 port.
Order T1 lines from the phone company. Contact your phone company
for more information about T1 lines and the services available for them.
for more information about T1 lines and the services available for them.