Configuring ATM Interface Encapsulation
To configure ATM encapsulation on a physical interface, include
the encapsulation statement at the [edit interfaces interface-name] hierarchy level:
- [edit interfaces interface-name]
- (atm-ccc-cell-relay |
atm-pvc | ethernet-over-atm);
For ATM interfaces, the physical interface encapsulation
can be one of the following:
- ATM cell-relay—This encapsulation connects two remote
virtual circuits or ATM physical interfaces with an LSP. Traffic on
the circuit is ATM cells.
- ATM PVC—ATM PVC encapsulation is defined in RFC
2684, Multiprotocol Encapsulation over ATM Adaptation Layer
5.
- Ethernet over ATM—As defined in RFC 1483 (the previous
version of RFC 2684), this encapsulation type allows ATM interfaces
to connect to devices that support only bridged-mode protocol data
units (BPDUs). The JUNOS software does not completely support bridging,
but accepts BPDU packets as a default gateway. If you use the router
as an edge device, then the router acts as a default gateway. It accepts
Ethernet LLC/SNAP frames with IP or ARP in the payload, and drops
the rest. For packets destined to the Ethernet LAN, a route lookup
is done using the destination IP address. If the route lookup yields
a full address match, the packet is encapsulated with an LLC/SNAP
and media access control (MAC) header, and the packet is forwarded
to the ATM interface.
Generally, you configure an interface’s encapsulation
at the [edit interfaces interface-name] hierarchy level. However, for ATM encapsulations, you can also configure
the encapsulation type that is used inside the ATM cell itself. To
do this, include the encapsulation statement:
- (atm-ccc-cell-relay |
atm-ccc-vc-mux | atm-cisco-nlpid | atm-mlppp-llc |
atm-nlpid | atm-ppp-llc | atm-ppp-vc-mux | atm-snap |
atm-tcc-snap | atm-vc-mux | atm-tcc-vc-mux | ether-over-atm-llc |
ether-vpls-over-atm-llc);
You can include this statement at the following hierarchy
levels:
- [edit interfaces interface-name unit logical-unit-number]
- [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number]
Table 1 shows the logical interface
encapsulation types for ATM interfaces.
Table 1: ATM Logical
Interface Encapsulation Types
Encapsulation Types
|
Comments
|
ATM CCC cell relay
|
This encapsulation type connects two remote virtual circuits
or ATM physical interfaces with an LSP.
This encapsulation type carries traffic in ATM cells.
When you use this encapsulation type, you can configure the ccc family only.
|
ATM CCC VC multiplex
|
This encapsulation type is for CCC circuits.
When you use this encapsulation type, you can configure the ccc family only.
|
ATM network layer protocol identifier (NLPID)
|
When you use this encapsulation type, you can configure
the inet family only.
|
ATM SNAP
|
|
ATM SNAP encapsulation on translational cross-connect
(TCC) circuits
|
When you use this encapsulation type, you can configure
the tcc family only.
|
ATM VC multiplex
|
When you use this encapsulation type, you can configure
the inet family only.
|
ATM VC multiplex on TCC circuits
|
When you use this encapsulation type, you can configure
the tcc family only.
|
Cell-relay accumulation mode (CAM)
|
In this mode, the incoming 1 to 8 cells are packaged
into a single packet and forwarded to the LSP. To configure CAM, include
the atm-cell-relay-accumulation statement at the [edit
chassis fpc slot-number pic pic-number] hierarchy level.
This encapsulation type is for ATM1 interfaces only.
For more information about CAM, see the JUNOS System Basics Configuration Guide.
|
Cisco ATM NLPID
|
When you use this encapsulation type, you can configure
the inet family only.
|
Ethernet over ATM
|
This encapsulation type is for interfaces that carry
IPv4 traffic.
When you use this encapsulation type, you cannot configure point-to-multipoint
interfaces.
|
Ethernet VPLS over ATM
|
This encapsulation type enables a VPLS instance to support
bridging between Ethernet interfaces and ATM interfaces, as described
in RFC 2684.
Use this encapsulation type to support IEEE 802.1p classification
binding on ATM VCs.
This encapsulation type is for ATM2 IQ interfaces only.
When you use this encapsulation type, you cannot configure point-to-multipoint
interfaces.
|
Multilink PPP over AAL5 LLC
|
This encapsulation type is for ATM2 IQ interfaces only.
When you use this encapsulation type, your routing platform
must be equipped with a Link Services or Voice Services PIC.
|
PPP over AAL5 LLC
|
This encapsulation type is for ATM2 IQ interfaces only.
When you use this encapsulation type, you cannot configure point-to-multipoint
interfaces.
|
PPP over AAL5 multiplex
|
This encapsulation type is for ATM2 IQ interfaces only.
When you use this encapsulation type, you cannot configure point-to-multipoint
interfaces.
|
Updated: 2009-04-07
