Service Distribution Points (Sdps); Sdp Binding - Alcatel-Lucent 7750 SR OS Service Manual

Service Distribution Points (SDPs)

A service distribution point (SDP) acts as a logical way to direct traffic from one SR-Series to
another SR-Series through a uni-directional (one-way) service tunnel. The SDP terminates at the
far-end SR-Series which directs packets to the correct service egress SAPs on that device. A
distributed service consists of a configuration with at least one SAP on a local node, one SAP on a
remote node, and an SDP binding the service to the service tunnel.
An SDP has the following characteristics:
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An SDP from the local device to a far-end SR-Series requires a return path SDP from the far-end
SR-Series back to the local SR-Series. Each device must have an SDP defined for every remote
router to which it wants to provide service. SDPs must be created first, before a distributed service
can be configured.

SDP Binding

To configure a distributed service from ALA-A to ALA-B, the SDP ID (1)
specified in the service creation process in order to "bind" the service to the tunnel (the SDP).
Otherwise, service traffic is not directed to a far-end point and the far-end SR-Series device(s)
cannot participate in the service (there is no service). To configure a distributed service from
ALA-B to ALA-A, the SDP ID (5) must be specified.
7750 SR OS Services Guide
An SDP is locally unique to a participating SR-Series. The same SDP ID can appear on
other SR-Series routers.
An SDP uses the system IP address to identify the far-end SR-Series edge router.
An SDP is not specific to any one service or any type of service. Once an SDP is created,
services are bound to the SDP. An SDP can also have more than one service type
associated with it.
All services mapped to an SDP use the same transport encapsulation type defined for the
SDP (either GRE or MPLS).
An SDP is a management entity. Even though the SDP configuration and the services
carried within are independent, they are related objects. Operations on the SDP affect all
the services associated with the SDP. For example, the operational and administrative
state of an SDP controls the state of services bound to the SDP.
Services
(Figure 8) must be
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