< draft-xie-ps-centralized-address-management-01.txt   draft-xie-ps-centralized-address-management-02.txt >
Internet Working Group C. Xie Internet Working Group C. Xie
Internet Draft Q. Sun Internet Draft Q. Sun
Intended status: Informational China Telecom Intended status: Informational China Telecom
Expires: January 2017 W. Xu Expires: September 2017 W. Xu
W. Liu W. Liu
Huawei Huawei
I. Farrer I. Farrer
N. Kowalewski N. Kowalewski
Deutsche Telekom AG Deutsche Telekom AG
July 8, 2016 Y. Cheng
China Unicom
March 12, 2017
Problem statement for centralized address management Problem statement for centralized address management
draft-xie-ps-centralized-address-management-01 draft-xie-ps-centralized-address-management-02
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
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This Internet-Draft will expire on January 8, 2017. This Internet-Draft will expire on September 11, 2017.
Copyright Notice Copyright Notice
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document authors. All rights reserved. document authors. All rights reserved.
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1. Introduction 1. Introduction
The increase in number, diversity and complexity of modern network The increase in number, diversity and complexity of modern network
devices and services bring new challenges for the management of devices and services bring new challenges for the management of
network resources, such as IP addresses, bandwidth, and services that network resources, such as IP addresses, bandwidth, and services that
utilize such resources. However, current approaches for address management utilize such resources. However, current approaches for address management
often result in sub-optimal allocation efficiency and significant often result in sub-optimal allocation efficiency and significant
complexity for using, sharing and sharing such resources. complexity for using, sharing and sharing such resources.
Address resources are often managed across multiple, partly disconnected Address resources are often managed across multiple, partly disconnected
technical systems which have limited means of model based interoperation. technical systems which have limited means of model based inter-operation.
In the interest of reducing complexity, improve utilization of resources In the interest of reducing complexity, improve utilization of resources
and reduce overall associated OPEX and CAPEX, operators are looking for and reduce overall associated OPEX and CAPEX, operators are looking for
an intelligent, agile and flexible integrated approach to control and an intelligent, agile and flexible integrated approach to control and
manage IP address resources. Assignment of such resources should be manage IP address resources. Assignment of such resources should be
possible across many services, and offer means of categorizing, selecting possible across many services, and offer means of categorizing, selecting
and decision making on the assignment and revocation of address resources. and decision making on the assignment and revocation of address resources.
? ?
Among the resources aforementioned, the relevance of address management Among the resources aforementioned, the relevance of address management
gained traction by operators as it is a fundamental precursor for the gained traction by operators as it is a fundamental precursor for the
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then compute and configure an optimized forwarding path between them. then compute and configure an optimized forwarding path between them.
In the examples above, the address allocation policy, e.g., specific In the examples above, the address allocation policy, e.g., specific
IP address assigned to a specific VM, usually originates from a IP address assigned to a specific VM, usually originates from a
management system, e.g, OSS, OpenStack, SDN controller, DHCP server management system, e.g, OSS, OpenStack, SDN controller, DHCP server
instance. Many such systems are configured rather statically, via CLI instance. Many such systems are configured rather statically, via CLI
or per configuration file. or per configuration file.
This approach poses the following problems for operators: This approach poses the following problems for operators:
o Low allocation efficiency due to pre-allocation o Low allocation efficiency due to pre-allocation
o Manual configuration of address policy, with risk for consistancy in o Manual configuration of address policy, with risk for consistency in
applying policy applying policy
o Complexity in making real-time changes to assignment o Complexity in making real-time changes to assignment
o Lack of an open, programmable interface between systems which o Lack of an open, programmable interface between systems which
requires IP addresses and the Management Systems handling the requires IP addresses and the Management Systems handling the
respective IP address resources respective IP address resources
Address pool management is a sub-issue of address management. Address pool management is a sub-issue of address management.
Currently, operators are facing the following issues: Currently, operators are facing the following issues:
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2. Conventions used in this document 2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. Terminology 3. Terminology
IPAM: IP address management IPAM: IP address management
I2AM: Interface to address management
I2APM: Interface to address pool management
4. Problems and Use Cases 4. Problems and Use Cases
The BNG, which manages one of more routable IP addresses on behalf of The BNG, which manages one of more routable IP addresses on behalf of
each subscriber, should be configured with the IP address pools allocated each subscriber, should be configured with the IP address pools allocated
to subscribers. However, operators are increasingly challenged by the IPv4 to subscribers. However, operators are increasingly challenged by the IPv4
address shortage and IPv4 address pools are scattered into many blocks as address shortage and IPv4 address pools are scattered into many blocks as
small as an IPv4/24 per in many cases. In the worst case configuration small as an IPv4/24 per in many cases. In the worst case configuration
of such address pools on a large number of Broadband Network Gateway (BNG) of such address pools on a large number of Broadband Network Gateway (BNG)
has to be done manually by for operators and is labor intensive. For large has to be done manually by for operators and is labor intensive. For large
scale MAN, there can a three digit number of BNGs to configure. scale MAN, there can a three digit number of BNGs to configure.
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small as an IPv4/24 per in many cases. In the worst case configuration small as an IPv4/24 per in many cases. In the worst case configuration
of such address pools on a large number of Broadband Network Gateway (BNG) of such address pools on a large number of Broadband Network Gateway (BNG)
has to be done manually by for operators and is labor intensive. For large has to be done manually by for operators and is labor intensive. For large
scale MAN, there can a three digit number of BNGs to configure. scale MAN, there can a three digit number of BNGs to configure.
? ?
Usual approaches of manual configuration on BNGs with such data in a static Usual approaches of manual configuration on BNGs with such data in a static
way will not only create great workload, it also limits utilization efficiency way will not only create great workload, it also limits utilization efficiency
of the address pools when the number of subscribers varies or shrinks at a given BNG of the address pools when the number of subscribers varies or shrinks at a given BNG
instance. instance.
With NFV technology maturing, it can be envisioned that the edge of the IP network With NFV technology maturing, it can be envisioned that the edge of the IP network
will become a software-based virtualized vBNG entity itself, so the network element will become a software-based virtualized vBNG entity itself, so the network element
itself is dynamically created and changed. Such virtualized network elements are going itself is dynamically created and changed. Such virtualized network elements are going
to become more common and may be launched and withdrawn dynamically, based on actual to become more common and may be launched and withdrawn dynamically, based on actual
traffic and user load, and an efficient dynamic assignments and re-use of address traffic and user load, and an efficient dynamic assignments and re-use of address
resources will be much more necessary than with a classical hardware-based entities resources will be much more necessary than with a classical hardware-based entities.
+---------------+ +---------------+
| Address | | Address |
| Management | | Management |
| Server | | Server |
+---------------+ +---------------+
| | | | | |
| | | | | |
| | | Configuration: | | | Configuration:
| | | IPv6 address pools | | | IPv6 address pools
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+--------+ ``'--'`` `''-''`` +--------+ ``'--'`` `''-''``
Figure 1 Address pools configuration on the BNGs Figure 1 Address pools configuration on the BNGs
Figure 1 illustrates address pool configuration for BNGs. Each BNG Figure 1 illustrates address pool configuration for BNGs. Each BNG
requires configuration with several IPv4 and IPv6 address pools used requires configuration with several IPv4 and IPv6 address pools used
? ?
for allocation to subscribers. Those address pools are configured for allocation to subscribers. Those address pools are configured
through an API from a centralized Address Management Server. Typical through an API from a centralized Address Management Server. Typical
examples include IPv4 and IPv6 address pool configuration. examples include IPv4 and IPv6 address pool configuration. The
centralized management approach is very crucial for dynamically
service creation that concerned Virtual BNGs
The second use case for address pool configuration is for IPv6 The second use case for address pool configuration is for IPv6
migration. IPv6 transition mechanisms (e.g. DS-Lite, lw4over6, etc.), migration. IPv6 transition mechanisms (e.g. DS-Lite, lw4over6, etc.),
need to be configured with address pools to be used as translated need to be configured with address pools to be used as translated
routable addresses. When high availability features, e.g. active- routable addresses. When high availability features, e.g. active-
active/active-standby failover mechanism, are used, different address active/active-standby failover mechanism, are used, different address
pools may need to be configured on each transition instance. This pools may need to be configured on each transition instance. This
will further increase the number of address pools that need to be will further increase the number of address pools that need to be
configured. configured.
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The Management System(SDN controller) get the IP address of the two The Management System(SDN controller) get the IP address of the two
inter-communication hosts from address management system through an inter-communication hosts from address management system through an
open, programmable interface, then the SDN controller could design an open, programmable interface, then the SDN controller could design an
optimized forwarding path, and deploy it into forwarding plane. optimized forwarding path, and deploy it into forwarding plane.
Another common model is that the MNS/OSS and IPAM perform address management Another common model is that the MNS/OSS and IPAM perform address management
on different levels of granularity. The overall authoritative ownership of on different levels of granularity. The overall authoritative ownership of
all address resources lies with the IPAM, and the resources available in all address resources lies with the IPAM, and the resources available in
there are subject to a formally regulated assignment process (e.g. ARIN, RIPE, there are subject to a formally regulated assignment process (e.g. ARIN, RIPE,
etc.). From IPAM, blocks of addresses can be requested according to inherently etc.). From IPAM, blocks of addresses can be requested according to inherently
defined IP Address assignment policy. Requests are made by or on behalf of IP address defined IP Address assignment policy. Requests are made by or on behalf of IP
consuming entities, typically by provisioning intermediaries like MNS, OSS. address consuming entities, typically by provisioning intermediaries like MNS,
These systems may further break down the resource according to application specific OSS. These systems may further break down the resource according to application
substructures (e.g. DNS, DHCPv4, DHCPv6, OpenStack, ...) and sub-delegate them as needed. specific substructures (e.g. DNS, DHCPv4, DHCPv6, OpenStack, ...) and sub-delegate
them as needed.
+---------------+ IP resource +----------------+ +---------------+ IP resource +----------------+
| | Request | | | | Request | |
| IPAM + <-----------------+ Management | | IPAM + <-----------------+ Management |
| - Resources | | System | | - Resources | | System |
| - Policies +-----------------> + e.g. OSS, NMS | | - Policies +-----------------> + e.g. OSS, NMS |
| | Configuration: | | | | Configuration: | |
+---------------+ IP address object +-------/-------+ +---------------+ IP address object +-------/-------+
| Configuration: | Configuration:
| IP address object | IP address object
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9.2. Informative References 9.2. Informative References
[WIKI] https://en.wikipedia.org/wiki/IP_address_management [WIKI] https://en.wikipedia.org/wiki/IP_address_management
10. Acknowledgments 10. Acknowledgments
The authors of this draft would like to thank the following persons The authors of this draft would like to thank the following persons
for the provided valuable feedback and contributions: Benoit Claise, for the provided valuable feedback and contributions: Benoit Claise,
Marc Blancet, Yu Fu, John Strassner, Jun Bi, Diego Lopez, Zhiheng Liu, Marc Blancet, Yu Fu, John Strassner, Jun Bi, Diego Lopez, Zhiheng Liu,
Laurent Ciavaglia, Fred Baker, Joel Jaeggli. Laurent Ciavaglia, Fred Baker, Joel Jaeggli, Will Liu, Giuseppe Fioccola.
Authors' Addresses Authors' Addresses
Chongfeng Xie Chongfeng Xie
China Telecom Beijing Research Institute China Telecom Beijing Research Institute
China Telecom Beijing Information Science&Technology Innovation Park China Telecom Beijing Information Science&Technology Innovation Park
Beiqijia Town Changping District Beijing 102209 China Beiqijia Town Changping District Beijing 102209 China
Email: xiechf@ctbri.com.cn Email: xiechf.bri@chinatelecom.cn
? ?
Qiong Sun Qiong Sun
China Telecom Beijing Research Institute China Telecom Beijing Research Institute
China Telecom Beijing Information Science&Technology Innovation Park China Telecom Beijing Information Science&Technology Innovation Park
Beiqijia Town Changping District Beijing 102209 China Beiqijia Town Changping District Beijing 102209 China
Email: sunqiong@ctbri.com.cn Email: sunqiong@ctbri.com.cn
Weiping Xu Weiping Xu
Huawei Technologies Co., Ltd. Huawei Technologies Co., Ltd.
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Bonn, NRW 53227 Bonn, NRW 53227
Germany Germany
Email: ian.farrer@telekom.de Email: ian.farrer@telekom.de
Normen B. Kowalewski Normen B. Kowalewski
Deutsche Telekom AG Deutsche Telekom AG
CTO-ATI, Landgrabenweg 151 CTO-ATI, Landgrabenweg 151
Bonn, NRW 53227 Bonn, NRW 53227
Germany Germany
Email: normen.kowalewski@telekom.de Email: normen.kowalewski@telekom.de
Ying Cheng
China Unicom
No.21 Financial Street, XiCheng District
Beijing 100033
China
Email: chengying10@chinaunicom.cn
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