Cisco Cisco ASR 5700
Mobility Management Entity Overview
Features and Functionality - Base Software ▀
MME Administration Guide, StarOS Release 18 ▄
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Globally Unique Temporary UE Identity (GUTI): The MME allocates a Globally Unique Temporary Identity
(GUTI) to the UE. A GUTI has; 1) unique identity for MME which allocated the GUTI; and 2) the unique
identity of the UE within the MME that allocated the GUTI.
identity of the UE within the MME that allocated the GUTI.
Within the MME, the mobile is identified by the M-TMSI.
The Globally Unique MME Identifier (GUMMEI) is constructed from MCC, MNC and MME Identifier (MMEI). In
turn the MMEI is constructed from an MME Group ID (MMEGI) and an MME Code (MMEC).
turn the MMEI is constructed from an MME Group ID (MMEGI) and an MME Code (MMEC).
The GUTI is constructed from the GUMMEI and the M-TMSI.
For paging, the mobile is paged with the S-TMSI. The S-TMSI is constructed from the MMEC and the M-TMSI.
The operator needs to ensure that the MMEC is unique within the MME pool area and, if overlapping pool areas are in
use, unique within the area of overlapping MME pools.
use, unique within the area of overlapping MME pools.
The GUTI is used to support subscriber identity confidentiality, and, in the shortened S-TMSI form, to enable more
efficient radio signaling procedures (e.g. paging and Service Request).
efficient radio signaling procedures (e.g. paging and Service Request).
Tracking Area Identity (TAI): Provides the function to assign the TAI list to the mobile access device to limit
the frequency of Tracking Area Updates in the network. The TAI is the identity used to identify the tracking
area or group of cells in which the idle mode access terminal will be paged when a remote host attempts to
reach that user. The TAI consists of the Mobile Country Code (MCC), Mobile Network Code (MNC) and
Tracking Area Code (TAC).
area or group of cells in which the idle mode access terminal will be paged when a remote host attempts to
reach that user. The TAI consists of the Mobile Country Code (MCC), Mobile Network Code (MNC) and
Tracking Area Code (TAC).
MME S1-AP UE Identity (MME S1-AP UE ID): This is the temporary identity used to identify a UE on the
S1-MME reference point within the MME. It is unique within the MME per S1-MME reference point instance.
ANSI T1.276 Compliance
ANSI T1.276 specifies security measures for Network Elements (NE). In particular it specifies guidelines for password
strength, storage, and maintenance security measures.
strength, storage, and maintenance security measures.
ANSI T1.276 specifies several measures for password security. These measures include:
Password strength guidelines
Password storage guidelines for network elements
Password maintenance, e.g. periodic forced password changes
These measures are applicable to the system and an element management system since both require password
authentication. A subset of these guidelines where applicable to each platform will be implemented. A known subset of
guidelines, such as certificate authentication, are not applicable to either product. Furthermore, the platforms support a
variety of authentication methods such as RADIUS and SSH which are dependent on external elements. ANSI T1.276
compliance in such cases will be the domain of the external element. ANSI T1.276 guidelines will only be implemented
for locally configured operators.
authentication. A subset of these guidelines where applicable to each platform will be implemented. A known subset of
guidelines, such as certificate authentication, are not applicable to either product. Furthermore, the platforms support a
variety of authentication methods such as RADIUS and SSH which are dependent on external elements. ANSI T1.276
compliance in such cases will be the domain of the external element. ANSI T1.276 guidelines will only be implemented
for locally configured operators.
APN Restriction Support
The APN-Restriction value may be configured for each APN in the P-GW and transferred to the MME. It is used to
determine, on a per-MS basis, whether it is allowed to establish EPS bearers to other APNs.
determine, on a per-MS basis, whether it is allowed to establish EPS bearers to other APNs.
The APN-Restriction value is defined in clause 15.4 of 3GPP TS 23.060. APN-Restriction affects multiple procedures,
such as Initial Attach, TAU, PDN connectivity, and inter-MME handovers. The MME saves the APN-Restriction value
received in create session response for an APN and uses the maximum of the values from the currently active PDNs in
the next create session request. If a PDN is disconnected, then the maximum APN-Restriction is adjusted accordingly.
such as Initial Attach, TAU, PDN connectivity, and inter-MME handovers. The MME saves the APN-Restriction value
received in create session response for an APN and uses the maximum of the values from the currently active PDNs in
the next create session request. If a PDN is disconnected, then the maximum APN-Restriction is adjusted accordingly.