3Com S7906E - Switch, Руководство по настройке

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1-3
Figure 1-2
Place of a label in a packet
Currently, the device does not support the cell mode.
LSR
A Label switching router (LSR) is a fundamental component on an MPLS network. All LSRs support
MPLS.
LSP
A Label switched path (LSP) is the path along which a FEC travels through an MPLS network. Along an
LSP, two neighboring LSRs are called upstream LSR and downstream LSR respectively. In
Figure 1-3 ,
R2 is the downstream LSR of R1, while R1 is the upstream LSR of R2.
Figure 1-3
Diagram for an LSP
An LSP is a unidirectional path from the ingress of the MPLS network to the egress. It functions like a
virtual circuit in ATM or frame relay. Each node of an LSP is an LSR.
Label distribution protocol
A label distribution protocol is a protocol used by MPLS for control. It has the same functions as a
signaling protocol on a traditional network. It classifies FECs, distributes labels, and establishes and
maintains LSPs.
MPLS supports multiple label distribution protocols of either of the following two types:
z
Those dedicated for label distribution, such as Label Distribution Protocol (LDP).
z
Those existing protocols that are extended to support label distribution, such as Border Gateway
Protocol (BGP) and Resource Reservation Protocol (RSVP).
In addition, you can configure static LSPs.