Juniper JUNOSE 11.2.X IP SERVICES, Configuration Manual

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depends on tighter coordination between network elements in the broadband access
network while not causing added burden to the operations support system (OSS) layer.
ANCP is an extension to GSMPv3 that functions as a control plane between a
service-oriented layer 3 edge device (the Broadband Remote Access Server) and a layer
2 access node. In this role, ANCP performs QoS-related, service-related, and
subscriber-related operations. These operations include the following:
• Dynamic discovery of the access topology and enabling an authentication server to
retrieve this information
•
Subscriber and service data retrieval from the OSS by the Broadband Remote Access
Server (B-RAS) and sending that information to the access node to simplify service
management (referred to as line configuration)
•
An optimized, layer 2 multicast (IGMP) replication
•
On-demand access-line testing (ANCP Operation, Administration, and Maintenance)
JunosE Software supports the use of RADIUS attributes to monitor ANCP-related
information, such as upstream and downstream data rates. For information about using
RADIUS attributes see
JunosE Broadband Access Configuration Guide .
Access Topology Discovery
Many queuing or scheduling mechanisms must avoid congestion within the access
network while contending with multiple flows and distinct QoS requirements. These
mechanisms require that B-RAS devices obtain information about the access network
topology, the links within that network, and their rates.
Operations support systems cannot enforce the consistency of this gathered information
in a reliable and scalable way. ANCP discovery enables the automated discovery of the
access network topology, resolving this problem.
Line Configuration
Following access topology discovery, the B-RAS can query a subscriber management
OSS component (for example, a RADIUS server) to retrieve subscriber authorization
data. This type of query is typically managed by the B-RAS, but in some cases (for
example, DSL-related enforcement) it can be useful to push service information to the
access node for local enforcement of the corresponding subscriber line. Using the line
configuration feature provides a more flexible way to achieve this on-demand service.
NOTE: JunosE Software supports only a CLI version of this feature.
Transactional Multicast
IP multicasting in access networks often involves an access server replicating the same
multicast stream to multiple subscribers. This type of replication wastes access bandwidth
when multiple subscribers access network services using the same access node. The
amount of multicast replication is based on the number of subscribers, rather than the
number of access nodes.
Copyright © 2010, Juniper Networks, Inc. 186
JunosE 11.2.x IP Services Configuration Guide