3Com 3C63100-AC-C - PathBuilder S600 Bridge/router Reference Manual page 180

180 C 5: C
HAPTER ONFIGURING
P B S600 M , P
ATH UILDER ODULES
The following settings are available for Service interworking mode:
Direct—Mode 1 mapping; matches DE value to CLP value. When the serial
port is in this mode, it does not translate between Frame Relay (NLPID)
encapsulation, rather it send it straight through the ATM network, possibly
onto a Frame Relay network or device.
Always-0—Mode 2 mapping, with the CLP field mapped to a constant value
of 0. Mode 2 is an operational method for indicating data congestion to either
the ATM or Frame Relay network. Mode 2 allows for translation between
NLPID and LLC-SNAP encapsulation. It is used when connecting a Frame Relay
device or network to a non-Frame Relay device or network. For example, if the
PathBuilder S600 is connecting a router/FRAD over an ATM network (public or
private) and at the other site a router with an ATM OC3 UNI is connected to
the WAN network, typically the router OC3 UNI does not support NLPID and
requires mode 2 mapping so that the packet can be encapsulated to LLC-SNAP.
Always-1—Mode 2 mapping, with the CLP field mapped to a constant value
of 1. Mode 2 is an operational method for indicating data congestion to either
the ATM or Frame Relay network. Mode 2 allows for translation between
NLPID and LLC-SNAP encapsulation. It is used when connecting a Frame Relay
device or network to a non-Frame Relay device or network. For example, if the
PathBuilder S600 is connecting a router/FRAD over an ATM network (public or
private) and at the other site a router with an ATM OC3 UNI is connected to
the WAN network, typically the router OC3 UNI does not support NLPID and
requires mode 2 mapping so that the packet can be encapsulated to LLC-SNAP.
CLP to DE Mapping—Cell Loss Priority field to Frame Relay Discard Eligibility field
mapping. This parameter defines the value to which DE will be set from incoming
ATM cells in outgoing Frame Relay frames. The available settings depend on what
interworking mode you have selected: Network or Service.
The following settings are available for Network interworking mode:
n
Direct—Mode 1 mapping; matches CLP value to DE value. When the serial
port is in this mode, it does not translate between Frame Relay (NLPID)
encapsulation, rather it sends it straight through the ATM network, possibly
onto a Frame Relay network or device.
None—No CLP to DE mapping.
The following settings are available for Service interworking mode:
n
Direct—Mode 1 mapping; matches CLP value to DE value. When the serial
port is in this mode, it does not translate between Frame Relay (NLPID)
encapsulation, rather it send it straight through the ATM network, possibly
onto a Frame Relay network or device.
Always-0—Mode 2 mapping, with the DE field mapped to a constant value of
0. Mode 2 is an operational method for indicating data congestion to either
the ATM or Frame Relay network. Mode 2 allows for translation between
NLPID and LLC-SNAP encapsulation. It is used when connecting a Frame Relay
device or network to a non-Frame Relay device or network. For example, if the
PathBuilder S600 is connecting a router/FRAD over an ATM network (public or
private) and at the other site a router with an ATM OC3 UNI is connected to
the WAN network, typically the router OC3 UNI does not support NLPID and
requires mode 2 mapping so that the packet can be encapsulated to LLC-SNAP.
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ORTS AND PPLICATIONS