Cisco ASR 5000 Series, Обзор продукта

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Mobility Management Entity Overview
Features and Functionality - Base Software ▀
Cisco ASR 5000 Series Product Overview ▄
OL-22938-02
IETF RFC 4960, Stream Control Transmission Protocol, December 2007
EPS bearer context processing is based on the APN that the subscriber is attempting to access. Templates for all of the
possible APNs that subscribers will be accessing must be configured within the system. Up to 1024 APNs can be
configured on the system.
Each APN template consists of parameters pertaining to how UE contexts are processed such as the following:
PDN Type:IPv4, IPv6, or IPv4v6
EPS Bearer Context timers
Quality of Service
A total of 11 EPS bearer per subscriber are supported. These could be all dedicated, or 1 default and 10 dedicated or any
combination of default and dedicated context. Note that there must be at least one default EPS Bearer context in order
for dedicated context to come up.
NAS Protocol Support
MME provides this protocol support between the UE and the MME. The NAS protocol includes following elementary
procedures for EPS Mobility Management (EMM) and EPS Session Management (ESM):
EPS Mobility Management (EMM)
This feature used to support the mobility of user equipment, such as informing the network of its present location and
providing user identity confidentiality. It also provides connection management services to the session management
(SM) sublayer.
An EMM context is established in the MME when an attach procedure is successfully completed. The EMM procedures
are classified as follows:
EMM Common Procedures : An EMM common procedure can always be initiated when a NAS signalling
connection exists.
Following are the common EMM procedure types:
Globally Unique Temporary Identity (GUTI) reallocation
Authentication and security mode
Identification
EMM information
EMM Specific Procedures : This procedure provides Subscriber Detach or de-registration procedure.
EMM Connection Management Procedures : This procedure provides connection management related
function like Paging procedure.
EPS Session Management (ESM)
This feature is used to provide the subscriber session management for bearer context activation, deactivation,
modification, and update procedures.