Atm-forum interface, Ethernet interface – Alcatel Carrier Internetworking Solutions 1000 ADSL User Manual
Page 42
ATM devices in the network. An end-to-end connection is established by linking
the virtual connections between devices. This requires all intermediate ATM
devices to have VPI/VCI assignments.
For the ATM network, these assignments are the responsibility of network
operators. These operators configure ATM devices to provide a Permanent Virtual
Connection (PVC) through the network. The PVC provides an always-on service.
Once the ADSL modem is connected to the subscriber line, an end-to-end
connection can be established.
A
A
A
T
T
T
M
M
M
-
-
-
F
F
F
o
o
o
r
r
r
u
u
u
m
m
m
I
I
I
n
n
n
t
t
t
e
e
e
r
r
r
f
f
f
a
a
a
c
c
c
e
e
e
If terminal equipment is connected to the modem’s ATMF-25 port, ATM service is
delivered to the PC. This means ATM cells from applications on the PC are
captured by the ATMF interface and cross-connected or switched to the ADSL
line.
An ATMF-25.6 PC-NIC is required to terminate the ATM connections in the PC.
The PC-NIC must support encapsulations and protocols described in RFC 1483
and RFC 2364.
The virtual channels cross-connected in the ADSL modem between the ATMF
interface and the ADSL line can have VPI/VCI values listed in table E. A
connection is possible only if the PC-NIC is sending and receiving ATM cells on
one (or more) of these virtual channels.
Table E. ATMF VPI/VCI Values
Parameter
Value
Meaning
VPI
0-5
Virtual Path Identifier
VCI
0-65535
Virtual Channel Identifier
E
E
E
t
t
t
h
h
h
e
e
e
r
r
r
n
n
n
e
e
e
t
t
t
I
I
I
n
n
n
t
t
t
e
e
e
r
r
r
f
f
f
a
a
a
c
c
c
e
e
e
The Ethernet interface terminates ATM connections, extracting frames from
arriving cells and encapsulating frames in departing cells. Only those frames
supported by the modem are extracted or encapsulated. Table F lists the
supported encapsulations and VPI/VCI values based on connection type.