IP Telephony Solution for Bangladesh Government
Dr. Moshiur Rahman
North South University
Md. Mohibul Islam
ID # 071681056
MS ETE: 605
IP Telephony is transport of telephone calls over the Internet, no matter whether
traditional telephony devices, multimedia PCs or dedicated terminals take part in the
calls and no matter whether the calls are entirely or only partially transmitted over the
Internet. IP Telephony or Internet Telephony (telephony on top of IP) refers to
Communications services carried over IP (Internet Protocol) rather than over the
Public Switched Telephone Network (PSTN). It turns the analog speech into a digital
representation and then transports the signal in IP packets to the recipient. IP
Telephony is designed for different network sizes. IP Telephony is designed to scale
over the whole Internet. It should offer an alternative to the PSTN, replicating the
PSTN services and adding new ones.
Standard protocols: media transport
• Protocols designed to deliver real time data to the remote entities:
– RTP (Real Time Protocol: IETF RFC 3550, July 2003)
• provides end-to-end network transport functions suitable for applications
transmitting real-time data, such as audio, video
– RTCP (Real Time Control Protocol: IETF RFC 3550, July 2003)
• control protocol to allow monitoring of the data delivery, and to provide minimal
control and identification functionalities
• RTP/RTCP are always sent on top of UDP (User Datagram Protocol) on IP-based
Network Protocol and Network Interface
Standard protocols: call signaling
• Before audio or video media can flow using RTP/RTCP Between two entities
– need of finding the remote device and to negotiate the means by which media will
flow between the two devices
• The protocols that are central to this process are referred to As call signaling
protocols, the two standardized are
– H.323 (ITU-T Study Group 16, version 5, 2003)
– SIP (Session Initiation Protocol, original IETF RFC 2543, Updated by IETF RFC
3261, June 2002)
– H.323 and SIP both have their origins in 1995
– H.323 enjoyed the first commercial success due to the fact that ITU Quickly
published the first standard in early 1996
– SIP progressed much more slowly in the IETF with the first recognized "standard"
published later in 1999
– SIP was revised over the years and re-published in 2002 as RFC 3261, which is the
currently recognized standard for SIP
– These delays in the standards process resulted in delays in market adoption of the
– Today H.323 is still having the bigger commercial market share but the trend is
• SIP was chosen as the official protocol by the 3GPP partnership
Internet Telephony Security
Need to be in the middle to perform some attacks (it is not very difficult to get in the
middle, and WLAN technology simplifies you the job)
– DNS (modify entries to point all traffic to a hacker's machine)
– DHCP (make all traffic go to hackers machine as default gateway, or change DNS
entry to point at hacker's machine so all names resolve to hacker's IP address)
– ARP (reply with hacker's MAC address, gratuitous ARPs or regular ARP replies)
– Flood CAM tables in switches to destroy existing MAC addr/port associations so all
traffic is broadcast out every port, and then use ARP attacks
– Routing protocols (change routing such that traffic physically passes through a
router/machine controlled by hacker)
– Spanning tree attacks to change layer 2 forwarding topology
– Physical insertion (e.g. PC with dual NIC cards, be it Ethernet based or WLAN-
Components of the solution
• Communication server:
– SIP and JAVA based software.
– Runs on Linux
• PSTN Gateway
– Cisco 36xx, AS5300/5350/5400
– Audio Codes
– IP phones
• Cisco family 79xx
– Analog phones, Fax, Modem Gateway
• Media Hub 4,16 ports
• Client Software:
– AOL Messenger
– Google Talk
– “Msn Messenger” (audio/video)
– Xten, Xlite SIP Soft Phone
BD ISPs to get exclusive right to internet telephony services
The government has decided to provide internet protocol (IP) telephony licenses to
help reduce the costs of international calls substantially and augment legal calls
through internet. The Bangladesh Telecommunication Regulatory Commission
(BTRC) will provide the IP telephony licenses only to the internet service providers
(ISPs) as part of its drive to legalize voice over internet protocol (VoIP) across the
country. The ISPs will be able to provide easy and affordable telecommunication
services to the people across the country by promoting and using the latest technology
under the recently approved International Long Distance Telecommunication Service
(ILDTS) Policy-2007. Under the ILDTS policy no mobile phone operators or the
fixed phone line operators will be eligible to get the IP telephony licenses, a senior
BTRC official told the FE quoting the policy provisions.
As per the section 11 of the ILDTS Policy, the BTRC will provide four types of
licenses - international gateway (IGW), interconnection exchange (ICX), Internet
Exchange (IX) and IP telephony - to open the VoIP services to private sector.
Keeping the IP telephony license reserved only for the ISPs the BTRC has kept the
licenses of the IGW, ICX and IX open. Section 12.5 of the ILDTS policy clarified it
further where it is mentioned that, "IP telephony licenses will be issued to ISP
operators except PSTN/PLMN operators having ISP licenses," For getting the IGW,
ICX and IX licenses the interested companies must have to take part in the auction
bidding process, said BTRC sources quoting ILDTS policy provision. The ISPs will,
however, get the IP telephony licenses directly without participating in the bidding, he
added. The ISPs will have to deposit certain amount of money to get the IP telephony
licenses, the ILDTS policy pointed out. Sources said the ISPs will provide IP
telephones to their clients across the country for making IP telephone calls in and
outside the country under the IP telephony licenses.
Currently the ISPs provide only internet services to their clients through the
submarine cables and very small aperture terminals (VSATs) across the country.
"The IP telephony operations by the ISPs will not only ensure government's tough
monitoring on calling over internet but also enhance government revenue
substantially," President of the Internet Service Providers Association of Bangladesh
(ISPAB) Mohammad Abdus Salam told the FE. Once initiated, the revenues of the
ISPs will augment substantially through IP telephony, he hoped. Expressing gratitude
to the BTRC for keeping the IP telephony licenses only for the ISPs, he said the
people will be able to make both local and international calls through IP telephones at
much cheaper rates.
Broadband Services in Bangladesh
BTTB has installed two PoPs at Dhaka (Moghbazar & Gulshan Exchange) and one
PoP at Chittagong (Nandankanon) to deliver higher bandwidth through optical fiber.
The optical fiber has to be arranged by the customer. BTTB provides only GE-SFP
port at Dhaka PoPs and GE-SFP/FE(electrical) port at Chittagong PoP for the
connection. Customers are requested to arrange the corresponding interface at their
end equipment. Specification of SFP at BTTB End is as follows:
1. Speed: 1250 Mbps (GE)
2. Distance: 10 km
3. Wavelength: 1310 nm
4. Mode: Single Mode (SM)
5. Transmit Power, Pout: -9.5 dBm (minimum) ~ -3 dBm (maximum)
6. Receive Power, Prec: -20 dBm (minimum) ~ -3dBm (maximum)
BTTB provides Leased Internet Access (Broadband) to corporate offices,
Universities, Financial organizations, International organizations etc. through DDN
nodes installed at 41 districts. 64 Kb/s to 2048 Kb/s Internet is being provided using
these nodes through commonly known telephone cables. This service is available
within the cable network of the following locations.
[Dhaka] Babubazar :: Basabo :: Cantonment :: ChawkBazar :: Demra :: DEPZ ::
Fakirapool :: Gandaria :: Gulshan :: Lalbag :: Mirpur :: Mogbazar :: Nilkhet :: Ramna
:: Savar :: Sayedabad :: Sher-e-Bangla Nagar :: Uttara
[Chittagong] Agrabad :: Bayezid :: CEPZ :: Kalurghat :: Muradpur :: Nandankanon ::
[Gazipur] Gazipur :: Tongi :: Konabari
[Narayangonj] Narayangonj :: Siddhirgonj
[Khulna] Central :: Khalishpur
[Pabna] Pabna :: Ishwardi
[Jessore] Jessore :: Sharsa
[Bagerhat] Bagerhat :: Mong
Telecom Companies in Bangladesh
1. Grameen Phone
5. Warid Telecom
6. Dhaka Phone
7. Worldtel etc.
Municipalities and other governmental entities tend to have multiple departments and
locations running on disparate – and often incompatible – technology infrastructures.
This can, and often does, pose significant maintenance and support challenges. The
adoption of IP telephony creates a single virtual telephony environment for various
departments spread throughout the city – or country. By unifying voice and data
technology infrastructures, maintenance and support are greatly simplified.
Furthermore, a single network can provide virtually every city employee with
traditional telephone services as caller ID, call forwarding, voice mail, and advanced
directory service – plus advanced IP telephone capabilities.
Chief Adviser's Office
Ministry of Finance
Ministry of Law, Justice & Parliamentary Affairs
Ministry of Agriculture
Ministry of Post and Tele-communication
Ministry of Information
Ministry of Foreign Affairs
Ministry of Planning
Ministry of Textiles and Jute
Ministry of Commerce
Ministry of Power, Energy and Mineral Resources
Ministry of Civil Aviation and Tourism
Ministry of Land
Ministry of Communications
Ministry of Industries
Ministry of Education
Ministry of Primary and Mass Education
Ministry of Science and Information & Communication Technology
Ministry of Home Affairs
Ministry of Health and Family Welfare
Firewall & Security Information
President's Office Chief Cabinet Division Ministry of Finance Ministry
Adviser's Office of
Essential Managed IP Telephony Service in Bangladesh
It provides complete management of IP Telephony infrastructure and applications, as
well as monitoring and incident management of the supporting data infrastructure.
24x7 monitoring of IP Telephony and data network for availability and
Incident management of IP Telephony and data network
Off-site configuration backup of IP Telephony infrastructure and applications
Change Management for IP Telephony platform and applications
Web portal access to real-time information about the customer’s network and
on-demand historical reports
Service Level Agreement defining objectives for system availability, IPT
quality-of-service and mean time to problem resolution
Change Management for routers and switches
Trend Analysis for IP Telephony and supporting data network
Dedicated Customer Service Manager assigned to monitor
Benefits of IP Telephony for BD Government
The entire all Bangladesh Ministry will be in one network.
All the Government office can communicate each other without any cost.
It will reduce total Government cost.
This system is much secured so it’ll be very helpful for BD Government.
It eliminates access line fees, charge and taxes.
Greater managerial control for all over the Government ministry.
Bangladesh defense can monitor all the time.
High officials can get more security from BD security forces.
It can supply voice, video, fax at a time so its vary helpful.
Government officials can perform their official task from remote area.
By the teleconference service army navy airfares can perform their specific
Government high officials can give instruction through teleconference.
Bangladesh agriculture can get help from this digital system.
Bangladesh police will be more efficient by the help of IP Telephony.
Education system will be more precious by IP Telephony.
Video conferencing can give help for student as well as teacher.
Public university will be more efficient.
BTTB will be more efficient and powerful.
In energy and power sector IP Telephony will have a great role.
Government research project will get help.
Bangladesh whole security system will be stronger.
Bangladesh sports will also get help through IP Telephony.