I2NSF Capability YANG Data Model
Huawei
7453 Hickory HillSalineMI48176USA+1-734-604-0332shares@ndzh.com
Department of Computer Science and Engineering
Sungkyunkwan University2066 Seobu-Ro, Jangan-GuSuwonGyeonggi-Do16419Republic of Korea+82 31 299 4957+82 31 290 7996pauljeong@skku.eduhttp://iotlab.skku.edu/people-jaehoon-jeong.php
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University2066 Seobu-Ro, Jangan-GuSuwonGyeonggi-Do16419Republic of Korea+82 10 8273 0930timkim@skku.edu
HTT Consulting
Oak ParkMIUSA+1-248-968-9809rgm@htt-consult.com
Huawei
Huawei Industrial BaseShenzhenGuangdong 518129Chinalinqiushi@huawei.com
Security
I2NSF Working GroupInternet-Draft
This document defines an information model and the corresponding YANG data model
for the capabilities of various Network Security Functions (NSFs) in the Interface
to Network Security Functions (I2NSF) framework to centrally manage the
capabilities of the various NSFs.
As the industry becomes more sophisticated and network devices (e.g., Internet-of-Things (IoT) devices, autonomous vehicles, and smartphones using Voice over IP (VoIP) and Voice over LTE (VoLTE)) require advanced security protection in various scenario, service providers have a lot of problems described in .
To resolve these problems, this document specifies the information and data models of the capabilities of Network Security Functions (NSFs) in a framework of the Interface to Network Security Functions (I2NSF) .
NSFs produced by multiple security vendors provide various security capabilities to customers. Multiple NSFs can be combined together to provide security services over the given network traffic,
regardless of whether the NSFs are implemented as physical or virtual functions. Security Capabilities describe the functions that Network Security Functions (NSFs) are available to provide for
security policy enforcement purposes. Security Capabilities are independent of the actual security control mechanisms that will implement them.
Every NSF SHOULD be described with the set of capabilities it offers. Security Capabilities enable security functionality to be described in a vendor-neutral manner. That is, it is not needed to
refer to a specific product or technology when designing the network; rather, the functions characterized by their capabilities are considered. Security Capabilities are a market enabler, providing
a way to define customized security protection by unambiguously describing the security features offered by a given NSF. Note that this YANG data model outlines an NSF monitoring YANG data model
and a YANG data model for Software-Defined Networking (SDN)-based IPsec flow protection .
This document provides an information model and the corresponding YANG data model that defines the capabilities of NSFs to centrally manage the capabilities of those security devices.
The security devices can register their own capabilities into a Network Operator Management (Mgmt) System (i.e., Security Controller) with this YANG data model through the registration interface .
With the database of the capabilities of those security devices that are maintained centrally, those security devices can be more easily managed .
This YANG data model uses an "Event-Condition-Action" (ECA) policy model that is used as the basis for the design of I2NSF Policy as described in and .
The "ietf-i2nsf-capability" YANG module defined in this document provides the following features:
Definition for time capabilities of network security functions.
Definition for event capabilities of generic network security functions.
Definition for condition capabilities of generic network security functions.
Definition for condition capabilities of advanced network security functions.
Definition for action capabilities of generic network security functions.
Definition for resolution strategy capabilities of generic network security functions.
Definition for default action capabilities of generic network security functions.
This document uses the terminology described in .
This document follows the guidelines of ,
uses the common YANG types defined in , and
adopts the Network Management Datastore Architecture (NMDA). The meaning of
the symbols in tree diagrams is defined in .
A Capability Information Model (CapIM) is a formalization of the functionality that an NSF advertises.
This enables the precise specification of what an NSF can do in terms of security policy enforcement,
so that computer-based tasks can unambiguously refer to, use, configure, and manage NSFs. Capabilities
MUST be defined in a vendor- and technology-independent manner (e.g., regardless of the differences
among vendors and individual products).
Humans can refer to categories of security controls and
understand each other. For instance, network security experts agree
on what is meant by the terms "NAT", "filtering", and "VPN concentrator".
As a further example, network security experts unequivocally refer
to "packet filters" as stateless devices that allow or deny
packet forwarding based on various conditions (e.g., source and
destination IP addresses, source and destination ports, and IP
protocol type fields) .
However, more information is required in case of other devices, like
stateful firewalls or application layer filters. These devices
filter packets or communications, but there are differences in the
packets and communications that they can categorize and the states
they maintain. Humans deal with these differences by asking more
questions to determine the specific category and functionality of
the device. Machines can follow a similar approach, which is
commonly referred to as question-answering . In this context, the CapIM and the derived
data model can provide important and rich information sources.
Analogous considerations can be applied for channel protection
protocols, where we all understand that they will protect packets by
means of symmetric algorithms whose keys could have been negotiated
with asymmetric cryptography, but they may work at different layers
and support different algorithms and protocols. To ensure
protection, these protocols apply integrity, optionally
confidentiality, anti-reply protections, and authentication.
The CapIM is intended to clarify these ambiguities by providing a
formal description of NSF functionality. The set of functions that
are advertised MAY be restricted according to the privileges of the
user or application that is viewing those functions. I2NSF
Capabilities enable unambiguous specification of the security
capabilities available in a (virtualized) networking environment,
and their automatic processing by means of computer-based
techniques.
This CapIM includes enabling a security controller in an I2NSF framework
to properly identify and manage NSFs, and allow
NSFs to properly declare their functionality through a Developer's Management
System (DMS) , so that they can be used in the
correct way.
This document defines an information model for representing NSF
capabilities. Some basic design principles for security capabilities
and the systems that manage them are:
Independence: Each security capability SHOULD be an independent
function, with minimum overlap or dependency on other
capabilities. This enables each security capability to be
utilized and assembled together freely. More importantly, changes
to one capability SHOULD NOT affect other capabilities. This
follows the Single Responsibility Principle .
Abstraction: Each capability MUST be defined in a vendor-
independent manner.
Advertisement: A dedicated, well-known interface MUST be used to
advertise and register the capabilities of each NSF. This same
interface MUST be used by other I2NSF Components to determine
what Capabilities are currently available to them.
Execution: Dedicated, well-known interfaces MUST be used to
configure and monitor the use of a capability, resepectively.
These provide a standardized ability to describe its functionality,
and report its processing results, resepectively. These facilitate
multi-vendor interoperability.
Automation: The system MUST have the ability to auto-discover,
auto-negotiate, and auto-update its security capabilities (i.e.,
without human intervention). These features are especially useful
for the management of a large number of NSFs. They are essential
for adding smart services (e.g., refinement, analysis, capability
reasoning, and optimization) to the security scheme employed.
These features are supported by many design patterns, including
the Observer Pattern , the Mediator Pattern
, and a set of Message Exchange Patterns
.
Scalability: The management system SHOULD have the capability to
scale up/down or scale in/out. Thus, it can meet various
performance requirements derived from changeable network traffic
or service requests. In addition, security capabilities that are
affected by scalability changes SHOULD support reporting
statistics to the security controller to assist its decision on
whether it needs to invoke scaling or not.
Based on the above principles, this document defines a capability
model that enables an NSF to register (and hence advertise) its set
of capabilities that other I2NSF Components can use. These
capabilities MAY have their access control restricted by a policy;
this is out of scope for this document. The set of capabilities
provided by a given set of NSFs unambiguously defines the security
services offered by the set of NSFs used. The security controller
can compare the requirements of users and applications with the set of
capabilities that are currently available in order to choose which
capabilities of which NSFs are needed to meet those requirements.
Note that this choice is independent of vendor, and instead relies
specifically on the capabilities (i.e., the description) of the
functions provided.
Furthermore, when an unknown threat (e.g., zero-day exploits and
unknown malware) is reported by an NSF, new capabilities may be
created, and/or existing capabilities may be updated (e.g., by
updating its signature and algorithm). This results in enhancing the
existing NSFs (and/or creating new NSFs) to address the new threats.
New capabilities may be sent to and stored in a centralized
repository, or stored separately in a vendor's local repository. In
either case, a standard interface facilitates this update process.
The "Event-Condition-Action" (ECA) policy model in
is used as the basis for the design of the capability model;
definitions of all I2NSF policy-related terms are also defined in
. The following three terms
define the structure and behavior of an I2NSF imperative policy rule:
Event: An Event is defined as any important occurrence in time of
a change in the system being managed, and/or in the environment
of the system being managed. When used in the context of I2NSF
Policy Rules, it is used to determine whether the condition
clause of an I2NSF Policy Rule can be evaluated or not. Examples
of an I2NSF Event include time and user actions (e.g., logon,
logoff, and actions that violate an ACL).
Condition: A condition is defined as a set of attributes,
features, and/or values that are to be compared with a set of
known attributes, features, and/or values in order to determine
whether or not the set of actions in that (imperative) I2NSF
Policy Rule can be executed or not. Examples of I2NSF conditions
include matching attributes of a packet or flow, and comparing
the internal state of an NSF with a desired state.
Action: An action is used to control and monitor aspects of flow-
based NSFs when the event and condition clauses are satisfied.
NSFs provide security functions by executing various Actions.
Examples of I2NSF actions include providing intrusion detection
and/or protection, web and flow filtering, and deep packet
inspection for packets and flows.
An I2NSF Policy Rule is made up of three Boolean clauses: an Event
clause, a Condition clause, and an Action clause. This structure is
also called an ECA (Event-Condition-Action) Policy Rule. A Boolean
clause is a logical statement that evaluates to either TRUE or
FALSE. It may be made up of one or more terms; if more than one term
is present, then each term in the Boolean clause is combined using
logical connectives (i.e., AND, OR, and NOT).
An I2NSF ECA Policy Rule has the following semantics:
IF <event-clause> is TRUE
IF <condition-clause> is TRUE
THEN execute <action-clause> [constrained by metadata]END-IFEND-IF
Technically, the "Policy Rule" is really a container that aggregates
the above three clauses, as well as metadata, which describe the
characteristics and behaviors of a capability (or an NSF). Aggregating metadata
enables a business logic to be used to prescribe a behavior. For
example, suppose a particular ECA Policy Rule contains three actions
(A1, A2, and A3, in that order). Action A2 has a priority of 10;
actions A1 and A3 have no priority specified. Then, metadata may be
used to restrict the set of actions that can be executed when the
event and condition clauses of this ECA Policy Rule are evaluated to
be TRUE; two examples are: (1) only the first action (A1) is
executed, and then the policy rule returns to its caller, or (2) all
actions are executed, starting with the highest priority.
The above ECA policy model is very general and easily extensible.
The concept of a "matched" policy rule is defined as one in which
its event and condition clauses both evaluate to true. To precisely
describe what an NSF can do in terms of security, that a policy rule
needs to describe the events that it can catch, the conditions it can
evaluate, and the actions that it can enforce.
Therefore, the properties to characterize the capabilities of an
NSF are as follows:
Ac is the set of Actions currently available from the NSF;
Ec is the set of Events that an NSF can catch. Note that for NSF
(e.g., a packet filter) that are not able to react to events,
this set will be empty;
Cc is the set of Conditions currently available from the NSF;
EVc defines the set of Condition Clause Evaluation Rules that can
be used by the NSF to decide when the Condition Clause is true
when the results of the individual Conditions under evaluation are
given.
Formally, two I2NSF Policy Rules conflict with each other if:
the Event Clauses of each evaluate to TRUE;
the Condition Clauses of each evaluate to TRUE;
the Action Clauses affect the same object in different ways.
For example, if we have two Policy Rules in the same Policy:
R1: During 8am-6pm, if traffic is external, then run through FWR2: During 7am-8pm, conduct anti-malware investigation
There is no conflict between R1 and R2, since the actions are
different. However, consider these two rules:
R3: During 8am-6pm, John gets GoldServiceR4: During 10am-4pm, FTP from all users gets BronzeService
R3 and R4 are now in conflict, between the hours of 10am and 4pm,
because the actions of R3 and R4 are different and apply to the same
user (i.e., John).
Conflicts theoretically compromise the correct functioning of
devices (as happened for routers several year ago). However, NSFs
have been designed to cope with these issues. Since conflicts are
originated by simultaneously matching rules, an additional process
decides the action to be applied, e.g., among the ones which the matching
rule would have enforced. This process is described by means of a
resolution strategy for conflicts.
On the other hand, it may happen that, if an event is caught, none
of the policy rules matches the event. As a simple case, no rules may match a
packet arriving at border firewall. In this case, the packet is
usually dropped, that is, the firewall has a default behavior to
manage the cases that are not covered by specific rules.
Therefore, this document introduces another security capability that serves to
characterize valid policies for an NSF that solve conflicts with
resolution strategies and enforce default actions if no rules match:
RSc is the set of Resolution Strategies that can be used to specify
how to resolve conflicts that occur between the actions of the
same or different policy rules that are matched and contained in
this particular NSF;
Dc defines the notion of a Default action. This action can be
either an explicit action or a set of actions.
This section provides an overview of how the YANG data model can be used in
the I2NSF framework described in .
shows the capabilities (e.g., firewall and
web filter) of NSFs in the I2NSF Framework.
As shown in this figure, an NSF Developer's Management System (DMS) can
register NSFs and the capabilities that the NSFs can support.
To register NSFs in this way, the DMS utilizes this standardized capability
YANG data model through the I2NSF Registration Interface .
That is, this Registration Interface uses the YANG module described in this
document to describe the capabilities of an NSF that is registered with the
Security Controller.
With the database of the capabilities of the NSFs that are maintained centrally,
the NSFs can be more easily managed, which can resolve many of the
problems described in .
In , a new NSF at a Developer's Management
System has capabilities of Firewall (FW) and Web Filter (WF), which are
denoted as (Cap = {FW, WF}), to support Event-Condition-Action (ECA) policy
rules where 'E', 'C', and 'A' mean "Event", "Condition", and "Action",
respectively. The condition involves IPv4 or IPv6 datagrams, and the action
includes "Allow" and "Deny" for those datagrams.
Note that the NSF-Facing Interface is used for
the Security Controller to configure the security policy rules of generic NSFs
(e.g., firewall) and advanced NSFs (e.g., anti-virus and Distributed-Denial-of-Service
(DDoS) attack mitigator) with the capabilities of the NSFs registered with the
Security Controller.
A use case of an NSF with the capabilities of firewall and web filter
is described as follows.
If a network administrator wants to apply security policy rules to block malicious users
with firewall and web filter, it is a tremendous burden for a network administrator
to apply all of the needed rules to NSFs one by one. This problem can be resolved
by managing the capabilities of NSFs as described in this document.
If a network administrator wants to block IPv4 or IPv6 packets from malicious
users, the network administrator sends a security policy rule to block the users
to the Network Operator Management System (i.e., Security Controller) using the
I2NSF Consumer-Facing Interface.
When the Network Operator Management System receives the security policy rule,
it automatically sends that security policy rule to appropriate NSFs
(i.e., NSF-m in Developer's Management System A and
NSF-1 in Developer's Management System B) which can support the capabilities (i.e., IPv6).
This lets an I2NSF User not consider which specific NSF(s)
will work for the security policy rule.
If NSFs encounter the suspicious IPv4 or IPv6 packets of malicious users, they can
filter the packets out according to the configured security policy rule.
Therefore, the security policy rule against the malicious users' packets can be
automatically applied to appropriate NSFs without human intervention.
This section shows a YANG tree diagram of capabilities of network security functions, as defined in the .
This section explains a YANG tree diagram of NSF capabilities and its features.
shows a YANG tree diagram of NSF capabilities.
The NSF capabilities in the tree include time capabilities, event capabilities,
condition capabilities, action capabilities, resolution strategy capabilities, and
default action capabilities.
Those capabilities can be tailored or extended according to a vendor's specific
requirements. Refer to the NSF capabilities information model for detailed discussion
in .
Time capabilities are used to specify the capabilities which describe when to execute the I2NSF policy rule.
The time capabilities are defined in terms of absolute time and periodic time.
The absolute time means the exact time to start or end.
The periodic time means repeated time like day, week, or month.
Event capabilities are used to specify the capabilities that describe an event that would trigger the evaluation of the condition clause of the I2NSF Policy Rule. The defined event capabilities are system event and system alarm.
Condition capabilities are used to specify capabilities of a set of attributes, features, and/or values that are to be compared with a set of known attributes, features, and/or values in order to determine whether a set of actions needs to be executed or not so that an imperative I2NSF policy rule can be executed.
In this document, two kinds of condition capabilities are used to classify different capabilities of NSFs such as generic-nsf-capabilities for generic
NSFs and advanced-nsf-capabilities for advanced NSFs.
First, the generic-nsf-capabilities define the common capabilities of NSFs such as IPv4 capability, IPv6 capability, TCP capability, UDP capability, SCTP capability, DCCP capability, ICMP capability, and ICMPv6 capability.
Second, the advanced-nsf-capabilities define advanced capabilities of NSFs such as anti-virus capability, anti-DDoS capability, Intrusion Prevention System (IPS) capability, HTTP capability, and VoIP/VoLTE capability.
Note that VoIP and VoLTE are merged into a single capability in this document
because VoIP and VoLTE use the Session Initiation Protocol (SIP)
for a call setup.
See for more information about the
condition in the ECA policy model.
Action capabilities are used to specify the capabilities that describe the control and monitoring aspects of flow-based NSFs when the event and condition clauses are satisfied.
The action capabilities are defined as ingress-action capability, egress-action capability, and log-action capability.
See for more information about the action in the ECA policy model.
Also, see Section 7.2 (NSF-Facing Flow Security Policy Structure) in
for more information about the ingress and egress actions.
In addition, see Section 9.1 (Flow-Based NSF Capability Characterization) in and Section 7.5 (NSF Logs) in
for more
information about logging at NSFs.
Resolution strategy capabilities are used to specify the capabilities that describe conflicts that occur between the actions of the same or different policy rules that are matched and contained in this particular NSF.
The resolution strategy capabilities are defined as First Matching Rule (FMR), Last Matching Rule (LMR), Prioritized Matching Rule (PMR), Prioritized Matching Rule with Errors (PMRE), and Prioritized Matching Rule with No Errors (PMRN).
See for more information about the resolution strategy.
Default action capabilities are used to specify the capabilities that describe how to execute I2NSF policy rules when no rule matches a packet.
The default action capabilities are defined as pass, drop, alert, and mirror.
See for more information about the default action.
IPsec method capabilities are used to specify capabilities of how to support an Internet Key Exchange (IKE) for the security communication.
The default action capabilities are defined as IKE or IKE-less.
See for more information about the SDN-based IPsec flow protection in I2NSF.
This section introduces a YANG module for NSFs' capabilities, as defined in the .
This YANG module imports from .
It makes references to
This document requests IANA to register the following URI in the
"IETF XML Registry" :
This document requests IANA to register the following YANG
module in the "YANG Module Names" registry :
This YANG module specified in this document make a trade-off between privacy and security.
Some part of the YANG data model specified in this document might use highly sensitive private data of the client.
The data used in this YANG data model can be used for the NSFs to improve the security of the network.
In regards to the privacy data used, the security for accessibility of the data should be tightly secured and monitored.
The Security Considerations are discussed in .
The YANG module specified in this document defines a data schema designed to be accessed through network management protocols such as NETCONF or RESTCONF .
The lowest layer of NETCONF protocol layers can use Secure Shell (SSH) as a secure transport layer.
The lowest layer of RESTCONF protocol layers can use HTTP over Transport Layer Security (TLS), that is, HTTPS as a secure transport layer.
The Network Configuration Access Control Model (NACM)
provides a means of restricting access to specific NETCONF or RESTCONF users to a
preconfigured subset of all available NETCONF or RESTCONF protocol operations and
contents. Thus, NACM can be used to restrict the NSF registration from unauthorized
users.
There are a number of data nodes defined in this YANG module that are writable,
creatable, and deletable (i.e., config true, which is the default).
These data nodes may be considered sensitive or vulnerable in some network environments.
Write operations to these data nodes could have a negative effect on network and security
operations. These data nodes are collected into a single list node.
This list node is defined by list nsf with the following sensitivity/vulnerability:
list nsf: An attacker could alter the security capabilities associated with an NSF
by disabling or enabling the functionality of the security capabilities of the NSF.
Some of the features that this document defines capability indicators for are
highly sensitive and/or privileged operations (e.g., listening to VoIP/VoLTE
audio to identify individuals and web filtering) that inherently require access
to individuals' private data. It is noted that private information is made
accessible in this manner. Thus, the nodes/entities given access to this data
need to be tightly secured and monitored, to prevent leakage or other
unauthorized disclosure of private data.
Refer to for the description of privacy aspects
that protocol designers (including YANG data model designers) should consider
along with regular security and privacy analysis.
Assigned Internet Protocol NumbersModeling and management of firewall policiesCan many agents answer questions better than oneNatural Language Question Answering: The View from HereEnterprise Integration PatternsAgile Software Development, Principles, Patterns, and Practiceshttp://www.oodesign.com/mediator-pattern.htmlhttp://www.oodesign.com/mediator-pattern.htmlhttp://www.oodesign.com/mediator-pattern.html
This section shows configuration examples of "ietf-i2nsf-capability" module for capabilities registration of general firewall.
This section shows a configuration example for the capabilities registration of a general firewall in either an IPv4 network or an IPv6 network.
shows the configuration XML for the capabilities registration of a general firewall as an NSF in an IPv4 network. Its capabilities are as follows.
The name of the NSF is general_firewall.
The NSF can inspect a protocol, a prefix of IPv4 addresses, and a range of IPv4 addresses for IPv4 packets.
The NSF can inspect an exact port number and a range of port numbers for the transport layer (TCP and UDP).
The NSF can control whether the packets are allowed to pass, drop, or alert.
In addition, shows the configuration XML for the capabilities registration of a general firewall as an NSF in an IPv6 network. Its capabilities are as follows.
The name of the NSF is general_firewall.
The NSF can inspect a protocol (Next-Header), a prefix of IPv6 addresses, and a range of IPv6 addresses for IPv6 packets.
The NSF can inspect an exact port number and a range of port numbers for the transport layer (TCP and UDP).
The NSF can control whether the packets are allowed to pass, drop, or alert.
This section shows a configuration example for the capabilities registration of a time-based firewall in either an IPv4 network or an IPv6 network.
shows the configuration XML for the capabilities registration of a time-based firewall as an NSF in an IPv4 network. Its capabilities are as follows.
The name of the NSF is time_based_firewall.
The NSF can execute the security policy rule according to absolute time and periodic time.
The NSF can inspect a protocol (Next-Header), an exact IPv4 address, and a range of IPv4 addresses for IPv4 packets.
The NSF can control whether the packets are allowed to pass, drop, or alert.
In addition, shows the configuration XML for the capabilities registration of a time-based firewall as an NSF in an IPv6 network. Its capabilities are as follows.
The name of the NSF is time_based_firewall.
The NSF can execute the security policy rule according to absolute time and periodic time.
The NSF can inspect a protocol (Next-Header), an exact IPv6 address, and a range of IPv6 addresses for IPv6 packets.
The NSF can control whether the packets are allowed to pass, drop, or alert.
This section shows a configuration example for the capabilities registration of a web filter.
shows the configuration XML for the capabilities registration of a web filter as an NSF. Its capabilities are as follows.
The name of the NSF is web_filter.
The NSF can inspect a URL matched from a user-defined URL Database.
User can add the new URL to the database.
The NSF can control whether the packets are allowed to pass, drop, or alert.
This section shows a configuration example for the capabilities registration of a VoIP/VoLTE filter.
shows the configuration XML for the capabilities registration of a VoIP/VoLTE filter as an NSF. Its capabilities are as follows.
The name of the NSF is voip_volte_filter.
The NSF can inspect a voice call id for VoIP/VoLTE packets.
The NSF can control whether the packets are allowed to pass, drop, or alert.
This section shows a configuration example for the capabilities registration of a HTTP and HTTPS flood mitigator.
shows the configuration XML for the capabilities registration of a HTTP and HTTPS flood mitigator as an NSF. Its capabilities are as follows.
The name of the NSF is http_and_https_flood_mitigation.
The NSF can control the amount of packets for HTTP and HTTPS packets, which are routed to the NSF's IPv4 address
or the NSF's IPv6 address.
The NSF can control whether the packets are allowed to pass, drop, or alert.
This work was supported by Institute of Information & Communications
Technology Planning & Evaluation (IITP) grant funded by the Korea
MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based
Security Intelligence Technology Development for the Customized Security
Service Provisioning).
This work was supported in part by the IITP grant funded by the MSIT (2020-0-00395,
Standard Development of Blockchain based Network Management Automation
Technology).
This document is made by the group effort of I2NSF working group.
Many people actively contributed to this document, such as Acee Lindem,
Roman Danyliw, and Tom Petch.
The authors sincerely appreciate their contributions.
The following are co-authors of this document:
Patrick Lingga
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: patricklink@skku.edu
Liang Xia
Huawei
101 Software Avenue
Nanjing, Jiangsu 210012
China
EMail: Frank.Xialiang@huawei.com
Cataldo Basile
Politecnico di Torino
Corso Duca degli Abruzzi, 34
Torino, 10129
Italy
EMail: cataldo.basile@polito.it
John Strassner
Huawei
2330 Central Expressway
Santa Clara, CA 95050
USA
EMail: John.sc.Strassner@huawei.com
Diego R. Lopez
Telefonica I+D
Zurbaran, 12
Madrid, 28010
Spain
Email: diego.r.lopez@telefonica.com
Hyoungshick Kim
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: hyoung@skku.edu
Daeyoung Hyun
Department of Computer Science and Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: dyhyun@skku.edu
Dongjin Hong
Department of Electronic, Electrical and Computer Engineering
Sungkyunkwan University
2066 Seo-ro Jangan-gu
Suwon, Gyeonggi-do 16419
Republic of Korea
EMail: dong.jin@skku.edu
Jung-Soo Park
Electronics and Telecommunications Research Institute
218 Gajeong-Ro, Yuseong-Gu
Daejeon, 34129
Republic of Korea
EMail: pjs@etri.re.kr
Tae-Jin Ahn
Korea Telecom
70 Yuseong-Ro, Yuseong-Gu
Daejeon, 305-811
Republic of Korea
EMail: taejin.ahn@kt.com
Se-Hui Lee
Korea Telecom
70 Yuseong-Ro, Yuseong-Gu
Daejeon, 305-811
Republic of Korea
EMail: sehuilee@kt.com