Network Working Group M. Chen, Ed.
Internet-Draft L. Zheng, Ed.
Intended status: Informational H. Liu
Expires: January 4, 2015 Y. Yin
R. Papneja
Huawei Technologies
G. Mirsky , Ed.
Ericsson
S. Abhyankar
Vodafone
G. Deng
CNNIC
Y. Huang
China Unicom
July 3, 2014
IP Flow Performance Measurement Framework
draft-chen-ippm-coloring-based-ipfpm-framework-02
Abstract
This document specifies a passive measurement method, the IP flow
performance measurement (IPFPM). With IPFPM, data packets are marked
into different blocks of markers by changing one or more bits of
packets. No additional delimiting packet is needed and the
performance be measured in-service and in-band without the insertion
of additional traffic.
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 RFC 2119 [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
Chen, et al. Expires January 4, 2015 [Page 1]
Internet-Draft IPFPM Framework July 2014
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 January 4, 2015.
Copyright Notice
Copyright (c) 2014 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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview and Concept . . . . . . . . . . . . . . . . . . . . 4
4. Reference Model and Functional Components . . . . . . . . . . 5
4.1. Reference Model . . . . . . . . . . . . . . . . . . . . . 5
4.2. Measurement Control Point . . . . . . . . . . . . . . . . 6
4.3. Measurement Agent . . . . . . . . . . . . . . . . . . . . 6
5. Period Number . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Re-ordering Tolerance . . . . . . . . . . . . . . . . . . . . 7
7. Packet Loss Measurement . . . . . . . . . . . . . . . . . . . 8
8. Packet Delay Measurement . . . . . . . . . . . . . . . . . . 9
9. Consideration on Marking Bits Selection . . . . . . . . . . . 10
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
11. Security Considerations . . . . . . . . . . . . . . . . . . . 11
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
13.1. Normative References . . . . . . . . . . . . . . . . . . 11
13.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Performance Measurement (PM) is an important tool for service
provider for Service Level Agreement (SLA) verification,
troubleshooting (e.g., fault localization or fault delimitation) and
network visualization. There are two class of measurement methods -
Chen, et al. Expires January 4, 2015 [Page 2]
Internet-Draft IPFPM Framework July 2014
active measurement method and passive measurement method. Active
method measures the performance or reliability parameter associated
with the transfer of traffic by generating and/or receiving packets
injected into the network. On the contrary, passive method measures
some performance or reliability parameter associated with the
existing traffic (packets) on the network. Both passive and active
methods have their strengths and should be regarded as complementary.
There are certain scenarios where active measurements alone is not
enough or applicable and passive measurements are
desirable[I-D.deng-ippm-passive-wireless-usecase].
With active measurement method, the rate, numbers and interval
between the injected packets may affect the accuracy of the results.
And for injected test packets it may not be guaranteed to always be
in-band with the data traffic in the pure IP network due to Equal
Cost Multi-Path (ECMP).
The Multiprotocol Label Switching (MPLS) PM protocol [RFC6374] for
packet loss is an example of passive performance measurement. By
periodically inserting auxiliary Operations, Administration and
Maintenance (OAM) packets, the traffic is delimited by the OAM
packets into consecutive blocks, and the receivers count the packets
and calculate the packets loss each block. However, solutions like
[RFC6374] depend on the fixed positions of the delimiting OAM packets
for packets counting, and thus are vulnerable to out-of-order arrival
of packets. This could happen particularly with out-of-band OAM
channels, but might also happen with in-band OAM because of the
presence of multipath forwarding within the network. Out of order
delivery of data and the delimiting OAM can give rise to inaccuracies
in the performance measurement figures. The scale of these
inaccuracies will depend on data speeds and the variation in
delivery, but with out-of-band OAM, this could result in significant
differences between real and reported performance.
This document specifies a passive measurement method, the IP flow
performance measurement (IPFPM). With IPFPM, data packets are marked
into different blocks of markers by changing one or more bits of
packets without altering normal processing in the network. No
additional delimiting packet is needed and the performance can be
measured in-service without the insertion of additional traffic.
Furthermore, because marking based IP performance measurement does
not require extra OAM packets for traffic delimitation, it can be
used in situations where there is packets re-ordering. IP Flow
Information eXport (IPFIX) [RFC7011] is used for reporting the
measurement data of IPFPM to a central calculation element for
performance metrics calculation. Several new Information Elements of
IPFIX are defined for IPFPM. These are described in the companion
document [draft-chen-ippm-ipfpm-report].
Chen, et al. Expires January 4, 2015 [Page 3]
Internet-Draft IPFPM Framework July 2014
2. Terminology
The acronyms used in this document will be listed here.
3. Overview and Concept
The concept of marking IP packets for performance measurement is
described in [I-D.tempia-opsawg-p3m]. Marking of packets in a
specific IP flow to different markings divides the flows into
different consecutive blocks. Packets in a block have same marking
and consecutive blocks will have different markings. This enables
the measuring node to count and calculate packet loss and/or delay
based for each block of markers without any additional auxiliary OAM
packets. The following figure (Figure 1) is an example that
illustrates the different markings in a single IP flow in alternate 0
and 1 blocks.
| 0 Block | 1 Block | 0 Block | 1 Block |
000000000000 111111111111 000000000000 111111111111
Figure 1: Packet Marking
For packet loss measurement, there are two ways to mark packets:
fixed packet numbers or fixed time period for each block of markers.
This document considers only fixed time period method. The sender
and receiver nodes count the transmitted and received packets/octets
based on each block of markers. By counting and comparing the
transmitted and received packets/octets, the packet loss can be
detected.
For packet delay measurement, there are two solutions. One is
similar to the packet loss, that it still marks the IP flows to
different blocks of markers and uses the time of the marking change
as the reference time for delay calculations. This solution requires
that there must not be any out-of-order packets; otherwise, the
result will not be accurate. Because it uses the first packet of
each block of markers for delay measurement, if there is packet
reordering, the first packet of each block at the sender will be
probably different from the first packet of the block at the
receiver. The alternate way is to periodically mark a single packet
in the IP flow. Within a given time period, there is only one packet
that can be marked. The sender records the timestamp when the marked
packet is transmitted, the receiver records the timestamp when
detecting the marked packet. With the two timestamps, the packet
delay can be computed.
Chen, et al. Expires January 4, 2015 [Page 4]
Internet-Draft IPFPM Framework July 2014
A centralized calculation element Measurement Control Point (MCP) is
introduced in Section 4.2 of this document, to collect the packet
counts and timestamps from the senders and receivers for metrics
calculation. The IP Flow Information eXport (IPFIX) [RFC7011]
protocol is used for collecting the performance measurement statistic
information [draft-chen-ippm-ipfpm-report]. For the statistic
information collected, the MCP has to know exactly what packet pair
counts (one from the sender and the other is from the receiver) are
based on the same block of markers and a pair of timestamps (one from
the sender and the other is from the receiver) are based on the same
marked packet. The "Period Number" based solution Section 5 is
introduced to achieve this.
For a specific IP flow to be measured, there may be one or more
upstream and downstream Measurement Agents (MAs)( Section 4.3). An
IP flow can be identified by the Source IP (SIP) and Destination IP
(DIP) addresses, and it may combine the SIP and DIP with any or all
of the Protocol number, the Source port, the Destination port, and
the Type of Service (TOS) to identify an IP flow. For each flow,
there will be a flow identifier that is unique within a certain
administrative domain. To simplify the process description, the
flows discussed in this document are all unidirectional. A
bidirectional flow can be seen as two unidirectional flows.
IFPFM supports the measurement of Multipoint-to-Multipoint (MP2MP)
flow, which satisfy all the scenarios that include Point-to-Point
(P2P), Point-to-Multipoint (P2MP), Multipoint-to-Point (MP2P), and
MP2MP. P2P scenario is obvious and can be used anywhere. P2MP and
MP2P are very common in mobile backhaul networks. For example, a
Cell Site Gateway (CSG) multi-homing to two Radio Network Controller
(RNC) Site Gateways (RSGs) is a typical network design. When there
is a failure, there is a requirement to monitor the flows between the
CSG and the two RSGs hence to determine whether the fault is in the
transport network or in the wireless network (typically called "fault
delimitation"). This is especially useful in the situation where the
transport network belongs to one service provider and wireless
network belongs to other service providers.
4. Reference Model and Functional Components
4.1. Reference Model
The reference model of the Passive Performance Measurements Framework
(PPMF) is introduced in [I-D.zheng-ippm-framework-passive]. It
describes the main functional components of the passive measurement
system, and the interactions between the components. The Measurement
Agent (MA) of IPFPM is equivalent to the MA of PPMF. The Measurement
Control Point (MCP) of IPFPM is the combined function of Controller
Chen, et al. Expires January 4, 2015 [Page 5]
Internet-Draft IPFPM Framework July 2014
and Collector of PPFM. IP Flow Information eXport (IPFIX) [RFC7011]
protocol is used for collecting the performance measurement data on
the MAs and reported to MCP. The details are specified in the
companion document [draft-chen-ippm-ipfpm-report]. The Control
between MCP and MAs are left for future study.
+-----+
+------| MCP |------+
| +-----+ |
+-----+ | +---/ \---+ | +-----+
| MA1 |---+ | | +---| MA3 |
+-----+ | | +-----+
+-----+ | | +-----+
| MA2 |------+ +------| MA4 |
+-----+ +-----+
Figure 1: IPFPM Reference Model
4.2. Measurement Control Point
The Measurement Control Point (MCP) is responsible for collecting the
measurement data from the Measurement Agents (MAs) and calculating
the performance metrics according to the collected measurement data.
For packet loss, based on each block of markers, the difference
between the total counts received from all upstream MAs and the total
counts received from all downstream MAs are the lost packet numbers.
The MCP must make sure that the counts from the upstream MAs and
downstream MAs are related to the same marking/packets block. For
packet delay (e.g., one way delay), the difference between the
timestamps from the downstream MA and upstream MA is the packet
delay. Similarly to packet loss, the MCP must make sure the two
timestamps are based on the same marked packet. This document
introduces a Period Number (PN) based synchronization mechanism which
is discussed in details in Section 5.
4.3. Measurement Agent
The Measurement Agent (MA) executes the measurement actions (e.g.,
marks the packets, counts the packets, records the timestamps, etc.),
and reports the data to the Measurement Control Point (MCP). Each MA
maintains two timers, one (C-timer, used at upstream MA) is for
marking change, the other (R-timer, used at downstream MA) is for
reading the packet counts and timestamps. The two timers have the
same time interval but are started at different time. A MA can be
either an upstream or a downstream MA: the role is specific to an IP
flow to be measured. For a specific IP flow, the upstream MA will
change the marking and read the packet counts and timestamps when the
C-timer expires, the downstream MA just reads the packets counts and
timestamps when the R-timer expires. The MA may delay the reading
Chen, et al. Expires January 4, 2015 [Page 6]
Internet-Draft IPFPM Framework July 2014
for certain time when R-timer expires, in order to tolerant certain
degree of packet re-ordering. Section 6 describes this in details.
For each Measurement Task (corresponding to an IP flow)
[I-D.zheng-ippm-framework-passive], a MA maintains a pairs of packet
counters and a timestamp counter for each block of markers. As for
the pair of packet counters, one is for counting packets and the
other is for counting octets.
5. Period Number
When data are collected on the upstream MA and downstream MA, e.g.
packet counts or timestamps, and periodically reported to the MCP,
certain synchronization mechanism is required to ensure the data
collected are correlated. This document introduces the Period Number
(PN) to help the MCP to determine whether any two or more packet
counts (from distributed MAs) are related to the same block of
markers or any two timestamps are related to the same marked packet.
Period Number assures the data correlation by literally split the
packets into different measurement period. The PN is generated each
time a MA reads the packet counts or timestamps, and is associated
with Each packet count and timestamp reported to the MCP. When the
MCP see e.g. two PN associated with two packet counts from a
upstream and downstream MA, it consider this two packet counts are
for the same measurement period by the same PN, i.e. this two packet
counts are related to the same block of markers. The assumption is
that the upstream and downstream MAs are time synchronized. This
requires that the upstream and downstream MAs having a certain time
synchronization capability (e.g., supporting the Network Time
Protocol (NTP) [RFC5905], or the IEEE 1588 Precision Time Protocol
(PTP) [IEEE1588].) The PN is calculated as the modulo of the local
time (when the counts or timestamps are read) and the interval of the
marking time period.
6. Re-ordering Tolerance
In order to allow for a certain degree of packets re-ordering, the
R-timer on downstream MA should be started delta-t (Δt) later
after the C-timer is started. Delta-t is a defined period of time
and should satisfies the following conditions:
(Time-L - Time-MRO ) < Δt < (Time-L + Time-MRO )
Where
Time-L: the link delay time between the sender and receiver;
Chen, et al. Expires January 4, 2015 [Page 7]
Internet-Draft IPFPM Framework July 2014
Time-MRO: the maximum re-ordering time difference; if a packet is
expected to arrive at t1 but actually arrives at t2, then the Time-
MRO = | t2 - t1|.
So, the R-timer should be started at "t + Δt" (where the t is
the time when C-timer started).
For simplicity, the C-timer should be started at the beginning of
each time period. This document recommends the implementation to
support at least these time periods (1s, 10s, 1min, 10min and 1h).
So, if the time period is 10s, the C-timer should be started at the
time of any multiples of 10 in seconds (e.g., 0s, 10s, 20s, etc.),
then the R-timer should be started (e.g., 0s+Δt, 10s+Δt,
20s+Δt, etc.). With this method, each MA can independently
start its C-timer and R-timer given that the clocks have been
synchronized.
7. Packet Loss Measurement
To simplify the process description, the flows discussed in this
document are all unidirectional. A bidirectional flow can be seen as
two unidirectional flows. For a specific flow, there will be
upstream and downstream MAs and upstream and downstream packet
counts/timestamp accordingly.
For packet loss measurement, this document defines the following
counters and quantities:
U-CountP[n][m]: U-CountP is a two-dimensional array that stores the
number of packets transmitted by each upstream MA in each marking
time period. Specifically, parameter "n" is the "period number" of
measured blocks of markers while parameter "m" refers to the m-th MA
of the upstream MAs.
D-CountP[n][m]: D-CountP is a two-dimensional array that stores the
number of packets received by each downstream MA in each marking time
period. Specifically, parameter "n" is the "period number" of
measured blocks of markers while parameter "m" refers to the m-th MA
of the downstream MAs.
U-CountO[n][m]: U-CountO is a two-dimensional array that stores the
number of octets transmitted by each upstream MA in each marking time
period. Specifically, parameter "n" is the "period number" of
measured blocks of markers while parameter "m" refers to the m-th MA
of the upstream MAs.
D-CountO[n][m]: D-CountO is a two-dimensional array that stores the
number of octets received by each downstream MA in each marking time
Chen, et al. Expires January 4, 2015 [Page 8]
Internet-Draft IPFPM Framework July 2014
period. Specifically, parameter "n" is the "period number" of
measured blocks of markers while parameter "m" refers to the m-th MA
of the downstream MAs.
LossP: the number of packets transmitted by the upstream MAs but not
received at the downstream MAs.
LossO: the total octets transmitted by the upstream MAs but not
received at the downstream MAs.
The total packet loss of a flow can be computed as follows:
LossP = U-CountP[1][1] + U-CountP[1][2] + .... + U-CountP[n][m] -
D-CountP[1][1] - D-CountP[1][2] - .... - D-CountP[n][m'].
LossO = U-CountO[1][1] + U-CountO[1][2] + .... + U-CountO[n][m] -
D-CountO[1][1] - D-CountO[1][2] - .... - D-CountO[n][m'].
Where the m and m' are the number of upstream MAs and downstream MAs,
respectively.
8. Packet Delay Measurement
For packet delay measurement, there will be only one upstream MA and
may be one or more (P2MP) downstream MAs. Although the marking based
IPFPM supports P2MP model, this document only discusses P2P model,
the P2MP model is left for future study. This document defines the
following timestamps and quantities:
U-Time[n]: U-Time is a one-dimension array that stores the time when
marked packets are sent; parameter "n" is the "period number" of
marked packets.
D-Time[n]: D-Time is a one-dimension array that stores the time when
marked packets are received; parameter "n" is the "period number" of
marked packets. This is only for P2P model.
D-Time[n][m]: D-Time a two-dimension array that stores the time when
the marked packet is received by downstream MAs at each marking time
period. Here, parameter "n" is the "period number" of marked packets
while parameter "m" refers to the m-th MA of the downstream MAs.
This is for P2MP model which is left for future study.
One-way Delay[n]: The one-way delay metric for packet networks is
described in [RFC2679]. The "n" identifies the "period number" of
the marked packet.
One-way Delay[1] = D-Time[1] - U-Time[1].
Chen, et al. Expires January 4, 2015 [Page 9]
Internet-Draft IPFPM Framework July 2014
One-way Delay[2] = D-Time[2] - U-Time[2].
...
One-way Delay[n] = D-Time[n] - U-Time[n].
In the case of two-way delay, the delay is the sum of the two one-way
delays of the two flows that have the same MAs but have opposite
directions.
Two-way Delay[1] = (D-Time[1] - U-Time[1]) + (D-Time'[1] -
U-Time'[1]).
Two-way Delay[2] = (D-Time[2] - U-Time[2]) + (D-Time'[2] -
U-Time'[2]).
...
Two-way Delay[n] = (D-Time[n] - U-Time[n]) + (D-Time'[n] -
U-Time'[n]).
Where the D-Time and U-Time are for one forward flow, the D-Time' and
U-Time' are for reverse flow.
9. Consideration on Marking Bits Selection
This document does not specify which bits should be used for marking;
it primarily introduces options that the operator can choose for
packet marking. This document introduces the following options:
1. For IPv4, there is only one bit (the last reserved bit of the
Flag field of the IPv4 header) in IP header that can be used for
marking. With one bit, at any time it can only be used for loss
or delay measurement and cannot be used for packet loss and delay
measurement simultaneously;
2. For IPv6, it can leverage the IPv6 extension header for marking,
for example, adding a new option to the Hop-by-Hop Options
header[RFC2460] for marking. More detail will be added in a
future version or in a separate document.
For the above options, the operators should carefully think of the
marking bits selection to make sure that the setting or changing of
the marking bits SHOULD NOT affect the normal packet forwarding and
process.
Chen, et al. Expires January 4, 2015 [Page 10]
Internet-Draft IPFPM Framework July 2014
The implementations SHOULD provide knobs for operators to configure
and change the marking bits according to their network design and
policies.
10. IANA Considerations
This document makes no request to IANA.
11. Security Considerations
This document specifies a passive mechanism for measuring packet loss
and delay within a Service Provider's network where the IP packets
are marked with the unused bits in IP head field, and then inserting
additional OAM packets during the measurement is avoided. Obviously,
such mechanism does not directly affect other applications running on
the Internet but may lead to potential affects to the measurement
itself.
First, the measurement itself may be affected by routers (or other
network devices) along the path of IP packets intentionally altering
the value of marking bits of packets. Just as mentioned before, the
mechanism specified in this document is just in the context of one
Service Provider's network, so the routers (or other network devices)
are controllable and thus this kind of attack can be omitted.
Second, the measurement can be harmed by attackers injecting
artificial traffic. Then authentication techniques, like digital
signatures, may be used to guard against such kind of attack.
12. Acknowledgements
The authors would like to thank Adrian Farrel for his review,
suggestion and comments to this document.
13. References
13.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
13.2. Informative References
[I-D.deng-ippm-passive-wireless-usecase]
Lingli, D., Zheng, L., and G. Mirsky, "Use-cases for
Passive Measurement in Wireless Networks", draft-deng-
ippm-passive-wireless-usecase-00 (work in progress), July
2014.
Chen, et al. Expires January 4, 2015 [Page 11]
Internet-Draft IPFPM Framework July 2014
[I-D.tempia-opsawg-p3m]
Capello, A., Cociglio, M., Castaldelli, L., and A. Bonda,
"A packet based method for passive performance
monitoring", draft-tempia-opsawg-p3m-04 (work in
progress), February 2014.
[I-D.zheng-ippm-framework-passive]
Zheng, L., Elkins, N., Lingli, D., Ackermann, M., and G.
Mirsky, "Framework for IP Passive Performance
Measurements", draft-zheng-ippm-framework-passive-01 (work
in progress), June 2014.
[IEEE1588]
IEEE, "1588-2008 IEEE Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and
Control Systems", March 2008.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, December
1998.
[RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
Delay Metric for IPPM", RFC 2679, September 1999.
[RFC3260] Grossman, D., "New Terminology and Clarifications for
Diffserv", RFC 3260, April 2002.
[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, September 2006.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008.
[RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, September 2011.
Chen, et al. Expires January 4, 2015 [Page 12]
Internet-Draft IPFPM Framework July 2014
[RFC7011] Claise, B., Trammell, B., and P. Aitken, "Specification of
the IP Flow Information Export (IPFIX) Protocol for the
Exchange of Flow Information", STD 77, RFC 7011, September
2013.
Authors' Addresses
Mach(Guoyi) Chen (editor)
Huawei Technologies
Email: mach.chen@huawei.com
Lianshu Zheng (editor)
Huawei Technologies
Email: vero.zheng@huawei.com
Hongming Liu
Huawei Technologies
Email: liuhongming@huawei.com
Yuanbin Yin
Huawei Technologies
Email: yinyuanbin@huawei.com
Rajiv Papneja
Huawei Technologies
Email: Rajiv.Papneja@huawei.com
Greg Mirsky (editor)
Ericsson
USA
Email: gregory.mirsky@ericsson.com
Chen, et al. Expires January 4, 2015 [Page 13]
Internet-Draft IPFPM Framework July 2014
Shailesh Abhyankar
Vodafone
Vodafone House, Ganpat Rao kadam Marg Lower Parel
Mumbai 40003
India
Email: shailesh.abhyankar@vodafone.com
Guangqing Deng
CNNIC
4 South 4th Street, Zhongguancun, Haidian District
Beijing
China
Email: dengguangqing@cnnic.cn
Yongliang Huang
China Unicom
Email: huangyl@dipmt.com
Chen, et al. Expires January 4, 2015 [Page 14]