Noninteractive Operation, Administration, And Maintenance; General Switch Management Protocol And Ancp - Cisco 10000 Series Configuration Manual

Access-Network Control Protocol Description
There are two methods you can use to map ports: configure all VLAN subinterfaces first, and the ANCP
neighbor mappings next. Or, you can configure the mappings directly under the interface.
For example, the following commands configure port mapping for Q-in-Q VLAN subinterfaces:
ancp neighbor name dslam-name id dslam-id dot1q outer-vlanid second-dot1q inner-vlanid [interface
interface] client-ID "Access-Loop-Circuit-ID"
or
ancp neighbor name dslam-name id dslam-id client-ID "Access-Loop-Circuit-ID"
The Access-Loop-Circuit-ID is a unique ID that the DSLAM sends to the BRAS for each unique port.
The DSLAM sends this ID in the ANCP Port Up event message. The circuit-ID uses a defined format
consisting of an Access-Node-Identifier and digital subscriber line (DSL) information as mentioned
below:
ATM/DSL
"Access-Node-Identifier atm slot/module/port.subinterface:vpi.vci"
Ethernet/DSL
"Access-Node-Identifier ethernet slot/module/port.subinterface[:vlan-id]"
The BRAS sets the default state as Down, on all ports of the router, until the DSLAM sends a Port Up
message.

Noninteractive Operation, Administration, and Maintenance

Layer 2 Tunneling Protocol (L2TP) provides an out-of-band control channel for performing
noninteractive operation, administration, and maintenance (OAM) operations from the broadband
remote access server. In this way, router operators can view the ANCP port state of specific DSLAM
ports. ANCP port state information is stored in the ANCP dynamic database on the BRAS.

General Switch Management Protocol and ANCP

ANCP is an extension of the General Switch Management Protocol (GSMP). GSMP defines a
master-slave neighbor relationship in which the master initiates a connection to a slave. In ANCP, this
master-slave relationship is reversed—the BRAS (master) listens and accepts incoming ANCP
connections from the DSLAM (slave). The DSLAM uses event messages to communicate asynchronous
events to the BRAS, such as topology changes and Port Down or Port Up events.
GSMP connectivity between the BRAS and the DSLAM occurs over TCP/IP (RFC 3293). The DSLAM
initiates the connection to the router and the router accepts the connection if the appropriate interface is
ANCP enabled.
The GSMP Adjacency Protocol establishes GSMP neighbor relationships.
1.
Cisco 10000 Series Router Access Network Control Protocol Configuration Guide
1-4
During the adjacency-building:
The DSLAM and router negotiate their capabilities and determine the synchronization state
a.
between the two ends.
b. GSMP detects whether the router and the DSLAM have retained a local information database
state in case of a transport failure, or whether both devices require a state update.
Chapter 1 Access-Network Control Protocol
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