Nokia 7705 SAR-W Series - Label Edge and Label Switch Routers

MPLS Guide MPLS and RSVP-TE
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At the egress LER:
config>router>entropy-label
config>router>rsvp>entropy-label-capability
config>router>mpls>lsp>entropy-label
config>router>isis>entropy-label>override-tunnel-elc
config>router>ospf>entropy-label>override-tunnel-elc
The per-service-hashing command and the l4-load-balancing,
teid-load-balancing, and spi-load-balancing commands are mutually exclusive.
For IP traffic, use the l4-load-balancing command. For IP traffic with mobile
payload, use the teid-load-balancing and/or the spi-load-balancing command.
3.2.4 Label Edge and Label Switch Routers
A 7705 SAR performs different functions based on its position in an LSP—ingress,
egress, or transit—as described in the following list:
• ingress Label Edge Router (iLER) — The router at the beginning of an LSP is
the iLER. The ingress router encapsulates packets with an MPLS header and
forwards the packets to the next router along the path. An LSP can only have
one ingress router.
• Label Switching Router (LSR) — An LSR can be any intermediate router in the
LSP between the ingress and egress routers, swapping the incoming label with
the outgoing MPLS label and forwarding the MPLS packets it receives to the
next router in the LSP. An LSP can have 0 to 253 transit routers.
• egress Label Edge Router (eLER) — The router at the end of an LSP is the
eLER. The egress router strips the MPLS encapsulation, which changes it from
an MPLS packet to a data packet, and then forwards the packet to its final
destination using information in the forwarding table. An LSP can have only one
egress router. The ingress and egress routers in an LSP cannot be the same
router.
A router in a network can act as an ingress, egress, or transit router for one or more
LSPs, depending on the network design.
Constrained-path LSPs are signaled and are confined to one Interior Gateway
Protocol (IGP) area. These LSPs cannot cross an autonomous system (AS)
boundary.