Establishing Subscriber Sessions; Subscriber Session Overview - Cisco ASR 9000 Series Configuration Manual

Establishing Subscriber Sessions

A subscriber accesses network resources through a logical connection known as subscriber session. This
chapter provides information about various types of subscriber sessions, namely IPoE and PPPoE, and IP
addressing by DHCP. This chapter covers these topics:
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Subscriber Session Overview

A session represents the logical connection between the customer premise equipment (CPE) and the network
resource. To enable a subscriber access the network resources, the network has to establish a session with the
subscriber. Each session establishment comprises of these phases:
When packets arrive on an access interface, an attempt is made to link that packet to a subscriber context.
Note
• For PPPoE sessions the Source MAC of the CPE, Access interface and PPPoE Session ID are used
• For IPoE sessions the Source MAC, Access interface and IP address are verified against the DHCP
If there is no match, the packet is mapped against the access (sub-)interface. Considering that the access
interface in IPoE designs is IP enabled (eg via an IP-Unnumbered configuration) that packets are processed
like regular IP. In order to secure your BNG access interface, you will want to apply either uRPF or an
Access-List blocking everything but DHCP incoming on the access interface to limit remote subscribers
for which we don't have an interface created from accessing network resources.
OL-26148-02
Subscriber Session Overview, page 55
Establishing IPoE Session, page 57
Establishing PPPoE Session, page 66
Making DHCP Settings, page 86
Packet Handling on Subscriber Interfaces, page 100
Additional References, page 101
to match the remote peer to a subscriber interface.
binding to find a matching subscriber interface.
Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Configuration Guide, Release
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C H A P T E R
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