ITU-T Workshop on
Bridging the Standardization Gap
and Interactive Training Session
(Nadi, Fiji, 4 – 6 July 2011 )
eGovernment IP Telephony Experience
in Korea
JayH Kim,
Xener Systems
Nadi, Fiji, 4 – 6 July 2011
Contents
IP Telephony & Unified Communication
1. Introduction to Korean e-Gov. IPT Project
2. Guidelines of Korea Government’s IPT
Copyright © 2009 Xener Systems, Inc. All Rights Reserved.
2
IP Telephony & Unified Communication
Introduction
Korean E-Gov. IP Telephony Project
Copyright © 2011 Xener Systems, Inc. All Rights Reserved.
3
South Korea ranks 1st in UN e-government survey
Quoted as “The country’s prize winning e-government system is expected to
serve as a model for many other countries planning to establish e-government
systems.”
Source of Article:
http://unpan.org/Library/MajorPublications/DELUNEGovernmentSurvey/PublicEGovernanceSurveyintheNe
ws/tabid/651/mctl/ArticleView/ModuleId/1555/articleId/22303/Default.aspx
4
Example of Benefits from e-Gov. Project
World’s Highest On-line survey Ratio in National Census (in 2011)
On-line Participation Ratio reaches 40%
756 households out of 1,889
households across the nation 
40.1%
The previous world record by Canada
was 18.5%(in 2006)
Savings as much as 18.4 Million USD
Initial forecasting: 30%  savings by 16.4 Million USD
Additional savings, 2M USD, thanks to 40% participation
5
Driving Forces of Gov. IPT Project
Korean Government’s Master plan:
 20% Cut down on telecommunication cost of each person
 Nationwide implementation of BcN (Broadband converged Network)
Korean Central Government complex IPT
Keeping pace with Internet Telephony widespread
Modernization of Telephony Network of Korean Gov.
Take an Initiative of Being a Reference Model of Gov. IPT
Korea Government Efforts for e-Gov. IPT
1
 Nov. 2008: Make a guideline for adopting VoIP by government
agencies
• Draw up a guideline to regulate the introduction of VoIP by government
organizations.
• Define roles for each entity
 Service operator: Network interworking and management
 Gov. team in charge: regulation for VoIP introduction and usage,
recommended vendors and specification
 Gov. organization: Budget for VoIP and implementation
2
 Dec. 2008: Plan for introduction of VoIP by Gov. organizations
• New-year Administrative Report to the President of Korea (2009)
3
 Feb ~ June. 2009 : Briefing Session about VoIP for Gov. agencies
 Explanation to Gov. agencies (2 times)
 to service operators (3 times)
Korea Government Efforts for e-Gov. IPT (continued)
4
5
6
7
 Mar. 2009: Set up a Test Bed to experience and promote VoIP
• Comprehensive test in interoperability and quality and security(encryption) and
standard-compliance
• With the group of system vendors and of service provider, respectively,
 July 2009: Selection of VoIP service operators
• who will manage and operate Gov. telephony system
• KT, SK Broadband, Samsung Networks, LG Dacom
 Aug. 2009: Make a plan for long-term development of Gov. VoIP.
• Research on VoIP usage and VoIP in general
• Phased deployment plan, planning of strategic projects, and effects expected
 Aug. 2009 ~ : VoIP deployment in Central Government Complex
•
•
•
•
The office of Prime minister
Ministry of Legislation
Ministry of Public Administration and Security
Ministry of Education, Science and Technology, etc.
Interworking with VoIP Service Operators
4 SPs were selected to serve government buildings with leased data lines.
Government organizations can choose a serving ITSP at their discretion.
KT
Commercial
Network
Internet Telephony
Network (KT)
SKBB
Commercial
Network
LGD
Commercial
Network
Internet Telephony
Network (SKBB)
Internet Telephony
Network (LGD)
IP network for government
IPT project
Public
Offices
IP-PBX
IP phones
Video phone
SSN
Commercial
Network
Internet Telephony
Network (SSN)
Benefits Gained through IPT
Pave the way for e-Government Goal, ‘All-IP e-Government’
Adopting TDM-free IP Telephony environment: called ‘Pure IP PBX’
Serves as a foundation for future advanced services
 IP Contact Center(Customer Service), UC(Unified Communication)
Top Level of Telephony Quality and Security
Quality control system ensures top-notch communication quality.
World-best reliable and powerful network infrastructure: IP backbone, Soft Switch,
Operator’s experience
Adopt enhanced VoIP security with a dedicated equipment for VoIP services
Trustworthy interworking with designated VoIP service operators
Improvement of Administrative Work Performance
Improvement in work efficiency and productivity on a fast network infrastructure
Increased satisfaction about public service
 Corporate ring-back tone
 Click-to-call on the Web: Direct access to Call Center
 1-person-1-phone: direct and fast reach to a public servant in service
Open doors to the public for convenient communication channel
IP Telephony & Unified Communication
The Guidelines
Korea Government’s IP Telephony
Copyright © 2011 Xener Systems, Inc. All Rights Reserved.
11
Guidelines for Korea Government’s IPT

Internet Telephony Security guideline

IP Telephony mutual supplementary service guideline

IP telephony – public agency – standard model

Usage of IP telephony

Design guide of government agency’s IP telephony network

E-Gov. IPT network usage guide

IP Telephone installation guide

IP Telephony Operation guide for Government Agencies
Key Points to be Considered
Openness / Stand Compliance / Service Availability / VoIP Security
• interoperable with various IP phones from many vendors
• No proprietary specification, strict compliance with int’l standards
Openness
IP-PBX
• Secure communication and auth.
• VoIP network protection
• Support for standard SIP Connect
• Integration with the existing equipments
H.323
SSW
PSTN
Standard
Compliance
• Service is always available
SIP
Num.
• Regardless of system fault, network fault, natural disaster
VoIP Security
Service
Availability
Key Points to be Considered
Key Point 1 : Openness
IPPBX accommodates diverse IP terminals, based on open technology and common standard.
 IP PBXs and IP phones should be compatible with each other, regardless of its manufacturers.

Vendor A
Vendor B
Vendor C
Vendor J
IP PBX
Vendor D
Vendor I
Standard SIP Protocol
(RFC 3261)
Vendor E
Vendor G
Vendor H
Vendor F
Benefit
a wide range of choice in IP terminals
 free from vendor lock-in(dependency)
 easy to secure compatible terminals and no worry about vendor bankruptcy

Key Points to be Considered
Key Point 2 : Standard Compliance

IP PBX must well interoperate with not only IP phones but also Soft Switch(IPT Toll).
① SSW <-> VoIP operator
①
SIP
•
SIP protocol (standard)
ITSP
•
National standard (by Gov.)
PSTN
② IP-PBX <-> SSW
IPT Toll
(SSW)
SIP-connect
②
PBX
E1/T1
IP-PBX
③
Access
Gateway
•
Trunk
Gateway
SIP
Analog Phones
Analog Phones
SIP Connect (int’l standard)
IP Phones
③ IP-PBX <-> IP Terminals
•
Specification for call features
•
SIP Protocol & Security
•
NAT traversal needed
Key Points to be Considered
Key Point 3 : Service Availability
 In case of system failure / network failure / power failure / natural disaster
 The telephone service continuity should be ensured
System Redundancy (Component Virtual IP Address)
Active
Standby
Data Redundancy (Heartbeat Link)
LAN I/F Redundancy
(System Virtual IP Address)
Data Link1
Data Link2

Redundancy (system / network interface / data / power)

Fallback for Power Failure / Interworking with PSTN network
PoE S/W
Key Points to be Considered
Key Point 4 : VoIP Security

Standard Recommendation for Authentication and Encryption
Item
Standard Recommendation
Device(Terminal) Authentication
PKI (Public Key Infrastructure)
User Authentication
HTTP Digest (RFC 2617)
Signaling Encryption
Media Encryption

Security Protocol
TLS v1.2 (RFC 5246)
Encryption Algorithm
International Standard Algorithm
Key Management
PKI
Security Protocol
sRTP (RFC 3711)
Encryption Algorithm
International Standard Algorithm
Message
Authentication Code
HMAC-SHA1 (RFC 2104)
Key Management
SDES (RFC 4568)
Internet Telephony Security Guideline for Government Agencies published by National Intelligence
Service (NIS) in 2005
Introduction Model of IPT for Gov.
IPT Service Infrastructure Configuration
Ministry of Public Administration and Security designated National Information and
Communication Service Providers . (B Group - internet service, C Group - internet telephony service)
 Gov. agencies use IPT service by utilizing IP infrastructure of B group providers and IPT systems
of C group providers.

ITSP 1
ITSP 2
ITSP 3
ITSP 4
ISP (KT)
ISP (SKBB)
• ITSP : Internet Telephony
Service Provider
• ISP : Internet Service Provider
Analog phone
Introduction Model of IPT for Gov.
3 Introduction Models (A, B and C)

Gov. agencies select appropriate model among 3 models according to the necessity and
characteristics of each agency
Model A
Model B
Model C
Replace legacy PBX and all analog
Replace legacy PBX with IP PBX
Maintain legacy PBX and analog
phones with IPT systems
Maintain existing analog phones
phones
and Introduce additional IP phones
Introduce additional IP PBX and IP
phones
ITSP infra
ITSP infra
PSTN network
ITSP infra
PSTN network
F/W
F/W
F/W
PSTN network
PABX
IP phone
IP PBX
IP phone
IP PBX
Analog phone
IP phone
IP PBX
Analog phone
IP phone, IP PBX, TG(Trunk
IP phone, IP PBX, TG(Trunk
IP phone, IP PBX, TG(Trunk
Gateway)
Gateway), AG(Access Gateway)
Gateway)
Introduction Standards of IPT for Gov.
The Standard for LAN Construction
 PoE switch
 Cabling

Complying with IEEE 8.2.3af

Provide electrical power to IP
phone and PC through UTP
cable


IP Phone and PC should share
 VLAN setting

By using VLAN technology,
one port of PoE switch.
separate Voice traffic and date
IP Phone has 2 Ethernet ports
traffic logically
and provide port switching
function. (LAN port, PC port)

Enhanced voice quality and
security
UPS
PoE switch
Voice traffic
: tagged 802.1q
Inline
power
Switching
Function
support

UPS : Uninterruptible power supply

PoE : Power of Ethernet
Sharing one port (IP phone and PC)
Data traffic
: untagged 802.3
Introduction Standards of IPT for Gov.
The Standard for WAN Construction
For reliable and high quality IPT service
 Gov. agency should select proper voice codec and design network bandwidth properly.

Standard for calculating network B/W
Codec
Type
Codec itself
B/W
Codec
Payload
G.711
64 Kbps
80 Byte
Size of VoIP
Header
+Trailer (in
Ethernet)
VoIP Payload
(IPv4) in
Ethernet
B/W
138 Byte
138Byte x 8 x (1000ms/10ms) = 110,400bps
= 110.4Kbps
68 Byte
68Byte x 8 x (1000ms/10ms) = 54,400bps
= 54.4Kbps
58 Byte
G.729
8 Kbps
10 Byte
The Standard for System Capacity Design – IP PBX
The capacity of IP PBX = The number of IP Phone users
 In case of subscribers growth, IP PBX’s capacity should be expanded without additional H/W
installation (Software-based license support)

Introduction Standards of IPT for Gov.
The Standard for System Capacity Design – Gateway
 Trunk Gateway port capacity
[Case 1] TG directly interworks with PSTN
[Case 2] Through TG, IP PBX interworks
with legacy PBX
network
IP PBX
IP PBX
The number of TG ports
= The number of lines from
telephone company
E1 PRI
DID/DOD
Calculate the number of TG ports
according to traffic volume
E1 PRI
E1 PRI
DID/DOD
 Analog Gateway port capacity

FXS port of AG accommodates analog phones and FAXs.

The number of FXS ports of analog gateway = the number of analog phones and FAXs
Introduction Standards of IPT for Gov.
The Standard for Integrated NMS Introduction
Integrated NMS : operation and management system for IPT systems (IP PBX, IP phones, TG)
 For more efficient operation and reliable IPT service, introduction for NMS is recommended.






Management
Operation
Monitoring
IP terminal Provisioning
F/W update
I-NMS
IPPBX
Gateway
SNMPv1/v2
IP phone
The Standard for IP Phone Introduction
PoE support / Menu button support / Setting through web browser support
 Switching function support (LAN configuration) / PSTN port support
 Secondary IP PBX address setting in case of system failure

The Standard for Access Gateway Introduction
Consist of at least one port FXS and FXO, Accommodate FAX (T.38 standard support)
 Secondary IP PBX address setting in case of system failure
 Setting through web browser support , Security standard support

Supplementary Services Guidelines
Supplementary services are divided into mandatory and optional services
 Gov. agencies should use mandatory supplementary services for cost reduction, improvement for
convenience and public administration service.
 Other supplementary service (optional) is optionally selected and used according to characteristics
and necessity .

Basic Supplementary Services [example]
 User Group Services












Call Hunt Group (M)
Call Blocking /Barring (O)
Call Restriction by Operator (O)
Malicious Call Trace (O)
Multiple calls per line appearance (O)
Multiple line appearance (O)
One Number Multi-phone (O)
Distinctive ring (O)
Intercom (O)
Group Call (O)
Direct Inward System Access (DISA) (O)
Auto Attendant (O)
※ M : mandatory, O : optional
 Subscriber Service















Calling Line Identification (M)
Caller ID Blocking (O)
Call forward (M)
Music-on-hold (M)
Call park / Parked call pickup (O)
Pickup (M)
Call Transfer (M)
Call Hold (M)
Call Back Busy Subscriber (O)
Wake-up Call (O)
Call Intrusion (O)
Call Override (O)
Privacy (O)
Do Not Disturb (DND) (O)
The Anonymous Call Rejection (ACR) (O)
Technology Specification and Interoperability
IP PBX
 Interworking feature

IP PBX interworks with various system and PSTN network via designated protocols
Interworking system
ITSP systems
SIP phone
protocol
SIP (RFC 3261 and Extension Method)
Authentication server
LDAP or
RADIUS
Billing server
RADIUS or FTP
NMS
SNMP v1/v2/v3
Gateway
 SIP handling feature (for interworking with ITSP network)

Register method handling / Invite method handling
 Authentication and encryption specification

Comply with Internet Telephony Security Guideline for Government Agencies published by
National Intelligence Service (NIS) in 2005
Technology Specification and Interoperability
IP Phone
 Codec

Audio : G.711 alaw, G.711 ulaw, G.729A, G.729B

Video : H.263(mandatory), H.264(high end) over CIF , over 30 frames/second

codec Negotiation feature
 Protocol

SIP, SNMP V1, V2, V3, TLS, SRTP
 Authentication and encryption specification

Comply with Internet Telephony Security Guideline for Government Agencies published by
National Intelligence Service (NIS) in 2005
 Standard for QoS

Packet Delay : less than 100 ms (END to END)

Jitter 10/20 ms, without Packet Loss (G.729) :R value over 70 / (G.711) : R value over 80

Call success rate : Over 97%

Maintaining long call (under the condition of using CODEC G.711/729 , over 12 hours

Silence Suppression, VAD (voice activity detection),, CNG (Comfort Noise Generation), etc.
Fault Handling Plan
Fault handling procedure
Fault
notification
Fault
detection
Report
&
Inspection
Fault
handling
Report
result of
fault handling
Fault Occur
Primary care (maintenance company)
Solve the
problem
Need
Technical support
Fault handing complete
& analyze
Call supplier’s engineer
Supplier’s engineer can’t solve the
problem
Help Desk of partner
Help desk can solve
the problem by itself
Call manufacturer’s engineer
Fault handling
Fault handling complete & report
Security Guideline for Gov. IP Telephony
NIS Security Review


At the planning stage, Gov. agency should take the security review by NIS
Introduce security systems have CC certificate and pass the security compliance verification test.
Strong Authentication and Encryption

To use IPT service safely

Accurate authentication and encryption for signal and voice are required.
Standard Recommendation for Authentication and Encryption
Item
Standard Recommendation
Device Authentication
PKI (Public Key Infrastructure)
User Authentication
HTTP Digest (RFC 2617)
Signaling Encryption
Media Encryption
Security Protocol
TLS v1.2 (RFC 5246)
Encryption Algorithm
International Standard Algorithm
Key Management
PKI
Security Protocol
sRTP (RFC 3711)
Encryption Algorithm
International Standard Algorithm
Message Authentication
Code
HMAC-SHA1 (RFC 2104)
Key Management
SDES (RFC 4568)
Security Guideline for Gov. IP Telephony
Security for External Section
 Before Providing National Information and Communication Service
(C group provider)
IP Network

Limited internet telephony service

Internal section : IPT service

External section : PSTN service
IP PBX
TGW
PSTN
IP phone
Business PC
 After Providing National Information and Communication Service (C group provider)

If the National Information and Communication service provider properly apply security
measures required by NIS, Gov. agencies use IPT service in all section. (internal and external )
ITSP
IP PBX
Back up
PSTN
TGW
IP phone
Business PC
Security Guideline for Gov. IP Telephony
Voice and Data Network Separation Plan (VLAN)

Integrated network have a higher risk of quality reduction /difficulty of expansion /wiretapping.

Separation between voice and date network is required.

Physical separation : cost rising

Logical separation(VLAN) is recommended.
: advanced security
: high increased management efficiency
Introduction of security system specialized for IPT

Detecting and blocking external attack with security system specialized for internet telephony

Firewall specialized for IPT

Intrusion detection(protection) system specialized for IPT
IPT F/W
IPT IDS(IPS)
Security Guideline for Gov. IP Telephony
Back up Configuration in Case of Failure
 System Redundancy (Active – Standby or Active – Active)
System Redundancy (Component Virtual IP Address)
1) Active
3) Standby
Active
1) Standby
2)Switch-over 3) Active
Standby
Sync.
Data Redundancy (Heartbeat Link)
LAN I/F Redundancy
(System Virtual IP Address)
Data Link1
l
l
l
l
Data Link2
Automatic Fail Detection (Heart-beat Check)
Auto Switch-over (within 5 seconds)
Call Status Preservation
DB/Data Synchronization (In-memory DB)
 Power Redundancy
PoE
 Fallback for Power Failure

Uninterruptible power supply(UPS)

PoE(Power of Ethernet) switch

IP phone supporting PoE
Inline
power
UPS
Introduction Standards of IPT for Gov.
Back up Configuration in Case of Failure
 Alternative Routing in case of IP Network Failure

In case of system failure / network failure / natural disaster

Providing internal and external call for such emergency call as 119 and back up call by
Interworking with PSTN network
ITSP 1
ITSP 2
ISP
X
Government Office
X
Government Office
All Requirement Compliant product - Xener
Redundancy
Inter
operability
Openness
Security
(IP sec & TLS)
Efficient
Total solution
Tested & Proven
Solution
IP Telephony & Unified Communication
Copyright © 2009 Xener Systems, Inc. All Rights Reserved.
34