RFC8127: Mobile Access Gateway Configuration Parameters Controlled by the Local Mobility Anchor
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Related keywords:
(Binding Refresh)
(Heartbeat)
Internet Engineering Task Force (IETF) D. Patki
Request for Comments: 8127 S. Gundavelli
Category: Standards Track Cisco
ISSN: 2070-1721 J. Lee
Sangmyung University
Q. Fu
China Mobile
L. Bertz
Sprint
August 2017
Mobile Access Gateway Configuration Parameters Controlled
by the Local Mobility Anchor
Abstract
This specification defines a new extension,
LMA-Controlled-MAG-Session-Params, to Proxy Mobile IPv6. This option
can be used by the local mobility anchor (LMA) in a Proxy Mobile IPv6
domain for signaling a mobile access gateway (MAG) on enforcing
specific values for various configuration parameters such as
heartbeat and binding refresh parameters.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8127.
Patki, et al. Standards Track [Page 1]
RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3
2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
3. Protocol Extension . . . . . . . . . . . . . . . . . . . . . 4
3.1. Format of the LCMP Sub-Options . . . . . . . . . . . . . 5
3.1.1. Binding Re-registration Control Sub-Option . . . . . 6
3.1.2. Heartbeat Control Sub-Option . . . . . . . . . . . . 7
4. Protocol Configuration Variables . . . . . . . . . . . . . . 8
4.1. Local Mobility Anchor -- Configuration Variables . . . . 8
5. Protocol Considerations . . . . . . . . . . . . . . . . . . . 9
5.1. Local Mobility Anchor Considerations . . . . . . . . . . 10
5.2. Mobile Access Gateway Considerations . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . 12
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
Patki, et al. Standards Track [Page 2]
RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
1. Introduction
A large Proxy Mobile IPv6 (PMIPv6) [RFC5213] deployment, such as
residential deployment, can have tens of thousands of mobile access
gateways (MAGs) spread across geographical locations. While it can
be operationally challenging to manage such a large number of MAGs,
it can also be very difficult to ensure configuration consistency
across all the MAGs if they are not centrally managed. Configuring
aggressive values of parameters such as re-registration timeout and
heartbeat interval can potentially create considerable signaling load
on the local mobility anchor (LMA). This document provides a new
option to enable the LMA to control various parameters on the MAG
such as the re-registration frequency [RFC5213] and heartbeat
frequency [RFC5847]. With this option, the configuration of these
tunable parameters enforced centrally from the LMA enables Service
Providers to have better control on the behavior of the MAGs with
deterministic signaling load on the LMA.
2. Conventions and Terminology
2.1. Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2.2. Terminology
All the terms used in this document are to be interpreted as defined
in [RFC5213], [RFC5847], and [RFC7563].
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RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
3. Protocol Extension
The LMA-Controlled MAG Parameters (LCMPs) option is a mobility header
option used to exchange information related to the parameters that an
LMA enforces on a MAG. This option can be included only in the Proxy
Binding Acknowledge (PBA) message, and there MUST NOT be more than a
single instance of this mobility option in a given PBA message. This
option MUST contain one or more LCMP sub-options. Each LCMP sub-
option carries a specific configuration parameter. The sub-options
are defined in Section 3.1. The LCMP option has an alignment
requirement of 4n+2 [RFC8200].
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LCMP Sub-Option(s) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: LMA-Controlled MAG Parameters Option
Type
MUST be set to the value of 62, indicating that it is an
LMA-Controlled-MAG-Parameters option.
Length
8-bit unsigned integer indicating the length in octets of the
option, excluding the Type and Length fields.
LCMP Sub-Option(s)
LCMP sub-options are described in the sections below. The sub-
options can be present in any order. Inclusion of any specific
sub-option is optional, but at least one sub-option MUST be
present.
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3.1. Format of the LCMP Sub-Options
The LCMP sub-options are used for carrying information elements
related to various parameters that need to be configured on the MAG.
These sub-options can be included in the LCMP option defined in
Section 3. The LCMP sub-options have an alignment requirement of 4n.
The format of this sub-option is as follows.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LCMP Type | LCMP Length | Sub-Option Data ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: LMA-Controlled MAG Parameters Sub-Option
Type
8-bit unsigned integer indicating the type of the LCMP sub-option.
This specification defines the following types:
0 - Reserved
1 - Binding Re-registration Control Sub-Option
2 - Heartbeat Control Sub-Option
Length
8-bit unsigned integer indicating the number of octets needed to
encode the Option Data, excluding the LCMP Type and LCMP Length
fields of the sub-option.
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3.1.1. Binding Re-registration Control Sub-Option
The Binding Re-registration Control Sub-Option is a mobility sub-
option carried in the LCMP mobility option defined in Section 3.
This sub-option carries timer values related to re-registration.
There MUST be no more than a single instance of this sub-option in
the LCMP option. The format of this sub-option is defined below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LCMP Type = 1 | LCMP Length | Re-registration-Start-Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Initial-Retransmission-Time | Maximum-Retransmission-Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Binding Re-registration Control Sub-Option
LCMP Type
1 for the Binding Re-registration Control Sub-Option.
LCMP Length
6
Re-registration-Start-Time
16-bit unsigned integer indicating the number of time units before
the expiry of the PMIPv6 binding lifetime when the registration
refresh process needs to be activated. One time unit is 4
seconds.
Initial-Retransmission-Time
16-bit unsigned integer indicating minimum delay in seconds before
the first Proxy Binding Update (PBU) retransmission of the
exponential backoff process.
Maximum-Retransmission-Time
16-bit unsigned integer indicating maximum delay in seconds before
the last PBU retransmission message of the exponential backoff
process.
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3.1.2. Heartbeat Control Sub-Option
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LCMP Type = 2 | LCMP Length | HB-Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HB-Retransmission-Delay | HB-Max-Retransmissions |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Heartbeat Control Sub-Option
LCMP Type
2 for the Heartbeat Control Sub-Option.
LCMP Length
6
HB-Interval
16-bit unsigned integer indicating the heartbeat interval, i.e.,
time delay in seconds after a successful heartbeat exchange
(heartbeat request followed by response) when the next heartbeat
exchange can be triggered.
HB-Retransmission-Delay
16-bit unsigned integer indicating minimum time delay in seconds
before a heartbeat message is retransmitted.
HB-Max-Retransmissions
16-bit unsigned integer indicating maximum number of heartbeat
retransmissions.
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RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
4. Protocol Configuration Variables
4.1. Local Mobility Anchor -- Configuration Variables
This specification defines the following variables to be configured
by the system management. The configured values for these protocol
variables MUST survive server reboots and service restarts.
EnableLCMPSubOptReregControl
This flag indicates the operational state of the Binding
Re-registration Control Sub-Option support. The default value of
this flag is (0), indicating that support for the Binding
Re-registration Control Sub-Option is disabled.
EnableLCMPSubOptHeartbeatControl
This flag indicates the operational state of the Heartbeat Control
Sub-Option support. The default value of this flag is (0),
indicating that support for the Heartbeat Control Sub-Option is
disabled.
The following variables MAY be defined at various granularities such
as per binding, per cluster of bindings, per peering MAG, per cluster
of peering MAGs, or any other custom grouping. Regardless of the
granularity of this configuration, the LMA MUST be able to determine
the value of these variables for every individual binding.
LCMPReregistrationStartTime
This variable is used to set the minimum time interval in number
of seconds before the expiry of the PMIPv6 binding lifetime when
the registration refresh process SHOULD be activated. The default
value of this variable is 10 units, where each unit is 4 seconds.
LCMPInitialRetransmissionTime
This variable is used to set the minimum delay in seconds before
the first PBU retransmission of the exponential backoff process.
This variable is the same as INITIAL_BINDACK_TIMEOUT mentioned in
Section 6.9.4 of [RFC5213]. The default value of this variable is
1 second.
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RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
LCMPMaximumRetransmissionTime
This variable is used to set the maximum delay in seconds before
the last PBU retransmission message of the exponential backoff
process. This variable is the same as MAX_BINDACK_TIMEOUT
mentioned in Section 6.9.4 of [RFC5213]. The default value of
this variable is 32 seconds.
LCMPHeartbeatInterval
This variable is used to set the time delay in seconds after a
successful heartbeat exchange (heartbeat request followed by
response) when the next heartbeat exchange can be triggered. The
default value of this variable is 60 seconds. The time delay
SHOULD NOT be less than 30 seconds or more than 3600 seconds. The
value of this variable MAY be derived from the variable
HEARTBEAT_INTERVAL defined in Section 5 of [RFC5847] if configured
on the LMA.
LCMPHeartbeatRetransmissionDelay
This variable is used to set the minimum time delay in seconds
before a heartbeat message is retransmitted. The value of this
variable SHOULD be less than LCMPHeartbeatInterval. The default
value of this variable is 5 seconds.
LCMPHeartbeatMaxRetransmissions
This variable is used to set the maximum number of heartbeat
retransmissions. The default value of this variable is 3. The
value of this variable MAY be derived from the variable
MISSING_HEARTBEATS_ALLOWED defined in Section 5 of [RFC5847] if
configured on the LMA.
5. Protocol Considerations
The following considerations apply to the LMA and the MAG.
For supporting this extension, the conceptual Binding Cache Entry
data structure maintained by the LMA, described in Section 5.1 of
[RFC5213], and the conceptual Binding Update List entry data
structure maintained by the MAG, described in Section 6.1 of
[RFC5213], need to be extended to store the information elements
related to the LCMP option that are defined below.
o LCMPReregistrationStartTime
o LCMPInitialRetransmissionTime
Patki, et al. Standards Track [Page 9]
RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
o LCMPMaximumRetransmissionTime
o LCMPHeartbeatInterval
o LCMPHeartbeatRetransmissionDelay
o LCMPHeartbeatMaxRetransmissions
5.1. Local Mobility Anchor Considerations
On receiving a PBU message [RFC5213] from a MAG, the LMA MUST check
if the variable EnableLCMPSubOptReregControl is configured and set to
(1). If yes, and if LCMPReregistrationStartTime,
LCMPInitialRetransmissionTime, and LCMPMaximumRetransmissionTime are
all set to NON_ZERO values, then it MUST include the Binding
Re-registration Control Sub-Option in the LCMP mobility option, which
is in turn included in the PBA message. If the variable
EnableLCMPSubOptReregControl is configured and set to (1), and if any
of LCMPReregistrationStartTime, LCMPInitialRetransmissionTime, and
LCMPMaximumRetransmissionTime is set to ZERO value, then the LMA MUST
report a configuration error and reject the binding request by
sending a PBA message with status code '128 - Reason Unspecified'
[RFC5213].
The LMA MUST also check if variable EnableLCMPSubOptHeartbeatControl
is configured and set to (1). If yes, and if LCMPHeartbeatInterval,
LCMPHeartbeatRetransmissionDelay, and LCMPHeartbeatMaxRetransmissions
are all set to NON_ZERO values, then it MUST include the Heartbeat
Control Sub-Option in the LCMP mobility option, which is in turn
included in the PBA message. If the variable
EnableLCMPSubOptHeartbeatControl is set to (1), and if any of
LCMPHeartbeatInterval, LCMPHeartbeatRetransmissionDelay, and
LCMPHeartbeatMaxRetransmissions is set to ZERO value, then the LMA
MUST report a configuration error and reject the binding request by
sending a PBA message with status code '128 - Reason Unspecified'
[RFC5213].
5.2. Mobile Access Gateway Considerations
If the PBA message [RFC5213] received from the LMA contains the LCMP
mobility option and the Binding Re-registration Control Sub-Option,
then the MAG MUST overwrite the timer parameters related to binding
re-registration that are configured locally on the MAG with the
parameters received in the Binding Re-registration Control Sub-
Option. If any of the parameters in the Binding Re-registration
Control Sub-Option are ZERO, then the PBA message MUST be ignored and
an error message SHOULD be logged.
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RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
Similarly, if the LCMP mobility option contains the Heartbeat Control
Sub-Option, then the MAG MUST overwrite the heartbeat-related timer
parameters configured locally on the MAG with the parameters received
in the Heartbeat Control Sub-Option. If any of the parameters in the
Heartbeat Control Sub-Option, except HB-Retransmission-Delay, are
ZERO, then the PBA message MUST be ignored and an error message
SHOULD be logged.
6. IANA Considerations
IANA has updated the "Mobile IPv6 parameters" registry as described
here.
o Action 1: This specification defines a new mobility header option,
"LMA-Controlled MAG Parameters". This mobility option is
described in Section 3. The type value 62 has been assigned for
this option in the "Mobility Options" registry, as defined in
[RFC6275].
o Action 2: This specification defines a new mobility sub-option
format, the LCMP sub-option. The format of this mobility sub-
option is described in Section 3.1. This sub-option can be
carried in the LCMP option. The type values for this sub-option
are managed by IANA, under the "LMA-Controlled MAG Parameters Sub-
Option Type Values" registry. Per this document, IANA has
reserved the following type values. Approval of new LCMP sub-
option type values are to be made through Expert Review [RFC8126].
+---+-----------------------------------------------------+
| 0 | Reserved |
+---+-----------------------------------------------------+
| 1 | Binding Re-registration Control Sub-Option |
+---+-----------------------------------------------------+
| 2 | Heartbeat Control Sub-Option |
+---+-----------------------------------------------------+
7. Security Considerations
The LCMP option defined in this specification allows the
configuration of re-registration and heartbeat frequencies. This
option is defined for carrying it in Proxy Binding Update and Proxy
Binding Acknowledgement messages. This option is carried like any
other mobility header option as specified and does not require any
special security considerations.
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RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<https://www.rfc-editor.org/info/rfc5213>.
[RFC5847] Devarapalli, V., Ed., Koodli, R., Ed., Lim, H., Kant, N.,
Krishnan, S., and J. Laganier, "Heartbeat Mechanism for
Proxy Mobile IPv6", RFC 5847, DOI 10.17487/RFC5847, June
2010, <https://www.rfc-editor.org/info/rfc5847>.
[RFC7563] Pazhyannur, R., Speicher, S., Gundavelli, S., Korhonen,
J., and J. Kaippallimalil, "Extensions to the Proxy Mobile
IPv6 (PMIPv6) Access Network Identifier Option", RFC 7563,
DOI 10.17487/RFC7563, June 2015,
<https://www.rfc-editor.org/info/rfc7563>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
8.2. Informative References
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
Patki, et al. Standards Track [Page 12]
RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
Acknowledgements
The authors would like to thank the DMM Working Group for all the
comments and discussions on this document. The authors would also
like to thank Suresh Krishnan, Ralph Droms, Mirja Kuhlewind, Alexey
Melnikov, and Ben Campbell for their review feedback.
The work of Jong-Hyouk Lee was supported by 'The Cross-Ministry Giga
KOREA Project' grant from the Ministry of Science, ICT and Future
Planning, Korea.
Patki, et al. Standards Track [Page 13]
RFC 8127 LMA-Controlled MAG Configuration Parameters August 2017
Authors' Addresses
Dhananjay Patki
Cisco
Cessna Business Park SEZ, Kadubeesanahalli
Bangalore, Karnataka 560087
India
Email: dhpatki@cisco.com
Sri Gundavelli
Cisco
170 West Tasman Drive
San Jose, CA 95134
United States of America
Email: sgundave@cisco.com
Jong-Hyouk Lee
Sangmyung University
31, Sangmyeongdae-gil, Dongnam-gu
Cheonan 31066
Republic of Korea
Email: jonghyouk@smu.ac.kr
Qiao Fu
China Mobile
Xuanwumenxi Ave. No.32
Beijing
China
Email: fuqiao1@outlook.com
Lyle T. Bertz
Sprint
Kansas
United States of America
Email: Lyle.T.Bertz@sprint.com
Patki, et al. Standards Track [Page 14]