Isis Working Group J. You
Internet-Draft Q. Liang
Intended status: Standards Track Huawei
Expires: April 1, 2016 K. Patel
Cisco Systems
P. Fan
China Mobile
September 29, 2015
IS-IS Extensions for Flow Specification
draft-you-isis-flowspec-extensions-02
Abstract
Dissemination of the Traffic flow information was first introduced in
the BGP protocol [RFC5575]. FlowSpec rules are used to distribute
traffic filtering rules that are used to filter Denial-of-Service
(DoS) attacks. For the networks that only deploy an IGP (Interior
Gateway Protocol) (e.g., IS-IS), it is required that the IGP is
extended to distribute Flow Specification or FlowSpec rules.
This document discusses the use cases for distributing flow
specification (FlowSpec) routes using IS-IS. Furthermore, this
document defines a new IS-IS FlowSpec Reachability TLV encoding
format that can be used to distribute FlowSpec rules, its validation
procedures for imposing the filtering information on the routers, and
a capability to indicate the support of FlowSpec functionality.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
You, et al. Expires April 1, 2016 [Page 1]
Internet-Draft ISIS FlowSpec September 2015
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 1, 2016.
Copyright Notice
Copyright (c) 2015 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Cases for IS-IS based FlowSpec Distribution . . . . . . . 3
3.1. IS-IS Campus Network . . . . . . . . . . . . . . . . . . 4
4. IS-IS Extensions for FlowSpec Rules . . . . . . . . . . . . . 4
4.1. FlowSpec Filters sub-TLV . . . . . . . . . . . . . . . . 6
4.1.1. Order of Traffic Filtering Rules . . . . . . . . . . 7
4.1.2. Validation Procedure . . . . . . . . . . . . . . . . 7
4.2. FlowSpec Action sub-TLV . . . . . . . . . . . . . . . . . 8
4.2.1. Traffic-rate . . . . . . . . . . . . . . . . . . . . 9
4.2.2. Traffic-action . . . . . . . . . . . . . . . . . . . 9
4.2.3. Traffic-marking . . . . . . . . . . . . . . . . . . . 9
4.2.4. Redirect-to-IP . . . . . . . . . . . . . . . . . . . 10
5. Redistribution of FlowSpec Rules . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6.1. FlowSpec Reachability TLV . . . . . . . . . . . . . . . . 11
6.2. FlowSpec Filters sub-TLV . . . . . . . . . . . . . . . . 11
6.3. FlowSpec Action sub-TLV . . . . . . . . . . . . . . . . . 11
7. Security considerations . . . . . . . . . . . . . . . . . . . 11
8. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 11
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
You, et al. Expires April 1, 2016 [Page 2]
Internet-Draft ISIS FlowSpec September 2015
1. Introduction
[RFC5575] defines Border Gateway Protocol protocol extensions that
can be used to distribute traffic flow specifications. One
application of this encoding format is to automate inter-domain
coordination of traffic filtering, such as what is required in order
to mitigate (distributed) denial-of-service attacks. [RFC5575]
allows flow specifications received from an external autonomous
system to be forwarded to a given BGP peer. However, in order to
block the attack traffic more effectively, it is better to distribute
the BGP FlowSpec rules to the customer network, which is much closer
to the attacker.
For the networks deploying only an IGP (e.g., IS-IS), it is expected
to extend the IGP (IS-IS in this document) to distribute FlowSpec
rules. This document discusses the use cases for distributing
FlowSpec rules using IS-IS. Furthermore, this document also defines
a new IS-IS FlowSpec Reachability TLV encoding format that can be
used to distribute FlowSpec rules to the edge routers in the customer
network, its validation procedures for imposing the filtering
information on the routers, and a capability to indicate the support
of Flowspec functionality.
The semantic content of the FlowSpec extensions defined in this
document are identical to the corresponding extensions to BGP
([RFC5575] and [I-D.ietf-idr-flow-spec-v6]). In order to avoid
repetition, this document only concentrates on those parts of
specification where IS-IS is different from BGP. The IS-IS flowspec
extensions defined in this document can be used to mitigate the
impacts of DoS attacks.
2. Terminology
This section contains definitions for terms used frequently
throughout this document. However, many additional definitions can
be found in [ISO-10589] and [RFC5575].
Flow Specification (FlowSpec): A flow specification is an n-tuple
consisting of several matching criteria that can be applied to IP
traffic, including filters and actions. Each FlowSpec consists of
a set of filters and a set of actions.
3. Use Cases for IS-IS based FlowSpec Distribution
For the networks deploying only an IGP (e.g., IS-IS), it is expected
to extend the IGP (IS-IS in this document) to distribute FlowSpec
rules, because when the FlowSpec rules are installed in the customer
network, they are closer to the attacker than when they are installed
You, et al. Expires April 1, 2016 [Page 3]
Internet-Draft ISIS FlowSpec September 2015
in the provider network. Consequently, the attack traffic could be
blocked or the suspicious traffic could be limited to a low rate as
early as possible.
The following sub-section discusses the use case for IS-IS based
FlowSpec rule distribution.
3.1. IS-IS Campus Network
For networks not deploying BGP, for example, the campus network using
IS-IS, it is expected to extend IS-IS to distribute FlowSpec rules as
shown in Figure 1. In this kind of network, the traffic analyzer
could be deployed with a router, then the FlowSpec rules from the
traffic analyzer need to be distributed to the other routers in this
domain using IS-IS.
+--------+
|Traffic |
+---+Analyzer|
| +--------+
|
|FlowSpec
|
|
+--+-------+ +----------+ +--------+
| Router A +-----------+ Router B +--------+Attacker|
+----------+ +----------+ +--------+
| | |
| IS-IS FlowSpec | Attack Traffic |
| | |
Figure 1: IS-IS Campus Network
4. IS-IS Extensions for FlowSpec Rules
This document defines a new IS-IS TLV, i.e. the FlowSpec reachability
TLV (TLV type: TBD1), which would be carried in an LSP (Link State
Protocol) Data Unit [ISO-10589], to describe the FlowSpec rules.
The FlowSpec Reachability TLV carries one or more FlowSpec entries.
Each FlowSpec entry consists of FlowSpec filters (FlowSpec filters
sub-TLVs), corresponding FlowSpec actions (FlowSpec action sub-TLVs).
The FlowSpec Reachability TLV is defined below in Figure 2:
You, et al. Expires April 1, 2016 [Page 4]
Internet-Draft ISIS FlowSpec September 2015
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 (TBD1) | Length | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length 1 | FlowSpec Entry 1 (variable) |
+-+-+-+-+-+-+-+-+ +
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length 2 | FlowSpec Entry 2 (variable) |
+-+-+-+-+-+-+-+-+ +
~ ~
+ +
|
Figure 2: FlowSpec Reachability TLV
Type: 1 octet. Type code is TBD1.
Length: 1 octet. The length field defines the length of the value
portion in octets (thus a TLV with no value portion would have a
length of 0).
Value: variable. The value field contains a "Flags" field and one
or more 2-tuples consisting of the Length and the FlowSpec entry.
Each 2-tuple starts with 1 octet of Length, and followed by a
variable length FlowSpec entry, which consists of FlowSpec filters
sub-TLVs and corresponding FlowSpec action sub-TLVs. The length
specifies the number of bytes of the FlowSpec entry.
Flags: One octet Field identifying Flags
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Reserved |L|
+-+-+-+-+-+-+-+-+
The least significant bit L is defined as a Leaking enable bit.
If set, the FlowSpec Reachability TLV SHOULD be flooded across the
entire routing domain. If the L flag is not set, the FlowSpec
Reachability TLV MUST NOT be leaked between levels. This bit MUST
NOT be altered during the TLV leaking. This Flags may be modified
by the IS-IS Speaker according to a local policy.
You, et al. Expires April 1, 2016 [Page 5]
Internet-Draft ISIS FlowSpec September 2015
4.1. FlowSpec Filters sub-TLV
IS-IS FlowSpec filters sub-TLV is one component of FlowSpec entry,
carried in the FlowSpec reachability TLV. It is defined below in
Figure 3.
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Type(TBD2/TBD3)| Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | |
+-+-+-+-+-+-+-+-+ +
~ Filters (variable) ~
+ +
| ... |
Figure 3: IS-IS FlowSpec Filters sub-TLV
Type: the TLV type (Type Code: TBD2 for IPv4 FlowSpec filters,
TBD3 for IPv6 FlowSpec filters)
Length: the size of the value field in octets
Flags: One octet Field identifying Flags
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
| Reserved |S|
+-+-+-+-+-+-+-+-+
The least significant bit S is defined as a strict filter check
bit. If set, strict validation rules outlined in the validation
section Section 4.1.2 need to be enforced.
Filters: the same as "flow-spec NLRI value" defined in [RFC5575]
and [I-D.ietf-idr-flow-spec-v6].
You, et al. Expires April 1, 2016 [Page 6]
Internet-Draft ISIS FlowSpec September 2015
Table 1: IS-IS Supported FlowSpec Filters
+------+------------------------+------------------------------+
| Type | Description | RFC/ WG draft |
+------+------------------------+------------------------------+
| 1 | Destination IPv4 Prefix| RFC5575 |
| | Destination IPv6 Prefix| I-D.ietf-idr-flow-spec-v6 |
+------+------------------------+------------------------------+
| 2 | Source IPv4 Prefix | RFC5575 |
| | Source IPv6 Prefix | I-D.ietf-idr-flow-spec-v6 |
+------+------------------------+------------------------------+
| 3 | IP Protocol | RFC5575 |
| | Next Header | I-D.ietf-idr-flow-spec-v6 |
+------+------------------------+------------------------------+
| 4 | Port | RFC5575 |
+------+------------------------+------------------------------+
| 5 | Destination port | RFC5575 |
+------+------------------------+------------------------------+
| 6 | Source port | RFC5575 |
+------+------------------------+------------------------------+
| 7 | ICMP type | RFC5575 |
+------+------------------------+------------------------------+
| 8 | ICMP code | RFC5575 |
+------+------------------------+------------------------------+
| 9 | TCP flags | RFC5575 |
+------+------------------------+------------------------------+
| 10 | Packet length | RFC5575 |
+------+------------------------+------------------------------+
| 11 | DSCP | RFC5575 |
+------+------------------------+------------------------------+
| 12 | Fragment | RFC5575 |
+------+------------------------+------------------------------+
| 13 | Flow Label | I-D.ietf-idr-flow-spec-v6 |
+------+------------------------+------------------------------+
4.1.1. Order of Traffic Filtering Rules
With traffic filtering rules, more than one rule may match a
particular traffic flow. The order of applying the traffic filter
rules is the same as described in Section 5.1 of [RFC5575] and in
Section 3.1 of [I-D.ietf-idr-flow-spec-v6].
4.1.2. Validation Procedure
[RFC5575] defines a validation procedure for BGP FlowSpec rules, and
[I-D.ietf-idr-bgp-flowspec-oid] describes a modification to the
validation procedure defined in [RFC5575] for the dissemination of
BGP flow specifications. The IS-IS FlowSpec should support similar
features to mitigate the unnecessary application of traffic filter
You, et al. Expires April 1, 2016 [Page 7]
Internet-Draft ISIS FlowSpec September 2015
rules. The IS-IS FlowSpec validation procedure is described as
follows.
When a router receives a FlowSpec rule including a destination prefix
filter from its neighbor router, it should consider the prefix filter
as a valid filter unless the S bit in the flags field of Filter TLV
is set. If the S bit is set, then the FlowSpec rule is considered
valid if and only if:
The originator of the FlowSpec rule matches the originator of the
best-match unicast route for the destination prefix embedded in
the FlowSpec.
The former rule allows any centralized controller to originate the
prefix filter and advertise it within a given IS-IS network. The
latter rule, also known as a Strict Validation rule, allows strict
checking and enforces that the originator of the FlowSpec filter is
also the originator of the destination prefix.
When multiple equal-cost paths exist in the routing table entry, each
path could end up having a separate set of FlowSpec rules.
When a router receives a FlowSpec rule not including a destination
prefix filter from its neighbor router, the validation procedure
described above is not applicable.
The FlowSpec filter validation state is used by an IS-IS speaker when
the filter is considered for an installation in its FIB. An IS-IS
speaker MUST flood IS-IS LSP containing a FlowSpec Reachability TLV
as per the rules defined in [ISO-10589] regardless of the validation
state of the prefix filters.
4.2. FlowSpec Action sub-TLV
There are one or more FlowSpec Action TLVs associated with a FlowSpec
Filters TLV. Different FlowSpec Filters TLV could have the same
FlowSpec Action TLVs. The following IS-IS FlowSpec action TLVs,
except Redirect, are same as defined in [RFC5575].
Redirect: IPv4 or IPv6 address. This IP address may correspond to a
tunnel, i.e., the redirect allows the traffic to be redirected to a
directly attached next-hop or a next-hop requiring a route lookup.
You, et al. Expires April 1, 2016 [Page 8]
Internet-Draft ISIS FlowSpec September 2015
Table 2: Traffic Filtering Actions in [RFC5575], etc.
+-------+-----------------+---------------------------------------+
| type | FlowSpec Action | RFC/WG draft |
+-------+-----------------+---------------------------------------+
| 0x8006| traffic-rate | RFC5575 |
| | | |
| 0x8007| traffic-action | RFC5575 |
| | | |
| 0x8108| redirect-to-IPv4| I-D.ietf-idr-flowspec-redirect-rt-bis |
| | |
| 0x800b| redirect-to-IPv6| I-D.ietf-idr-flow-spec-v6 |
| | | |
| 0x8009| traffic-marking | RFC5575 |
+-------+-----------------+---------------------------------------+
4.2.1. Traffic-rate
Traffic-rate TLV is encoded as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD4 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic-rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Traffic-rate: the same as defined in [RFC5575].
4.2.2. Traffic-action
Traffic-action TLV is encoded as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD5 | 2 | Reserved |S|T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
S flag and T flag: the same as defined in [RFC5575].
4.2.3. Traffic-marking
Traffic-marking TLV is encoded as:
You, et al. Expires April 1, 2016 [Page 9]
Internet-Draft ISIS FlowSpec September 2015
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD6 | 2 | Reserved | DSCP Value|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
DSCP value: the same as defined in [RFC5575].
4.2.4. Redirect-to-IP
Redirect-to-IPv4 is encoded as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD7 | 6 | Reserved |C|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Redirect to IPv6 TLV is encoded as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD8 | 18 | Reserved |C|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6 Address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv4/6 Address: the redirection target address.
'C' (or copy) bit: when the 'C' bit is set, the redirection applies
to copies of the matching packets and not to the original traffic
stream [I-D.ietf-idr-flowspec-redirect-ip].
5. Redistribution of FlowSpec Rules
An implementation MAY provide an option for an IS-IS speaker to
announce a redistributed FlowSpec route within an IS-IS domain
regardless of being installed in its local FIB. An implementation
MAY impose an upper bound on number of FlowSpec rules that an IS-IS
router MAY advertise.
You, et al. Expires April 1, 2016 [Page 10]
Internet-Draft ISIS FlowSpec September 2015
6. IANA Considerations
This document defines the following new IS-IS TLV types, which need
to be reflected in the IS-IS TLV codepoint registry.
6.1. FlowSpec Reachability TLV
+------+---------------------------------+-----+-----+-----+
| Type | Description | IIH | LSP | SNP |
+------+---------------------------------+-----+-----+-----+
| TBD1 | The FlowSpec Reachability TLV | n | y | n |
+------+---------------------------------+-----+-----+-----+
6.2. FlowSpec Filters sub-TLV
+--------+-----------------------+--------------------------+
| Type | Description | encoding |
+--------+-----------------------+--------------------------+
| TBD2 |The FlowSpec filters | flow-spec NLRI value |
| TBD3 | sub-TLV | [RFC5575] |
| | |I-D.ietf-idr-flow-spec-v6 |
+--------+-----------------------+--------------------------+
6.3. FlowSpec Action sub-TLV
This document defines a group of FlowSpec actions. The following TLV
types need to be assigned:
Type TBD4 - traffic-rate
Type TBD5 - traffic-action
Type TBD6 - traffic-marking
Type TBD7 - redirect to IPv4
Type TBD8 - redirect to IPv6
7. Security considerations
This extension to IS-IS does not change the underlying security
issues inherent in the existing IS-IS. Implementations must assure
that malformed TLV and Sub-TLV permutations do not result in errors
which cause hard IS-IS failures.
8. Acknowledgement
The authors would like to thank Jeff Haas for his valuable comments.
You, et al. Expires April 1, 2016 [Page 11]
Internet-Draft ISIS FlowSpec September 2015
9. References
9.1. Normative References
[ISO-10589]
ISO, "Intermediate System to Intermediate System intra-
domain routeing information exchange protocol for use in
conjunction with the protocol for providing the
connectionless-mode network service (ISO 8473)",
International Standard 10589: 2002, Second Edition, 2002.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <http://www.rfc-editor.org/info/rfc4360>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<http://www.rfc-editor.org/info/rfc5575>.
9.2. Informative References
[I-D.ietf-idr-bgp-flowspec-oid]
Uttaro, J., Filsfils, C., Smith, D., Alcaide, J., and P.
Mohapatra, "Revised Validation Procedure for BGP Flow
Specifications", draft-ietf-idr-bgp-flowspec-oid-02 (work
in progress), January 2014.
[I-D.ietf-idr-flow-spec-v6]
Raszuk, R., Pithawala, B., McPherson, D., and A. Andy,
"Dissemination of Flow Specification Rules for IPv6",
draft-ietf-idr-flow-spec-v6-06 (work in progress),
November 2014.
[I-D.ietf-idr-flowspec-redirect-ip]
Uttaro, J., Haas, J., Texier, M., Andy, A., Ray, S.,
Simpson, A., and W. Henderickx, "BGP Flow-Spec Redirect to
IP Action", draft-ietf-idr-flowspec-redirect-ip-02 (work
in progress), February 2015.
You, et al. Expires April 1, 2016 [Page 12]
Internet-Draft ISIS FlowSpec September 2015
[I-D.ietf-idr-flowspec-redirect-rt-bis]
Haas, J., "Clarification of the Flowspec Redirect Extended
Community", draft-ietf-idr-flowspec-redirect-rt-bis-05
(work in progress), July 2015.
Authors' Addresses
Jianjie You
Huawei
101 Software Avenue, Yuhuatai District
Nanjing, 210012
China
Email: youjianjie@huawei.com
Qiandeng Liang
Huawei
101 Software Avenue, Yuhuatai District
Nanjing, 210012
China
Email: liangqiandeng@huawei.com
Keyur Patel
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95124 95134
USA
Email: keyupate@cisco.com
Peng Fan
China Mobile
Email: fanpeng@chinamobile.com
You, et al. Expires April 1, 2016 [Page 13]