Showing posts with label Internet. Show all posts
Showing posts with label Internet. Show all posts

Thursday, May 21, 2015

An Overview of the Products, Services and Business potentials of the Submarine Cable in Bangladesh


Md. Monwar Hossain                                                                                Parvez M. Ashraf    


Introduction

Bangladesh possesses great potentials in the ICT and Telecommunication sectors. As we are regularly experiencing, there is an increasing trend of using computers and availing mobile phone facilities or even the Tabs in the rural areas as in the urban areas of the Country. Bangladesh has got natural competitive advantage in terms of manpower, location and cost for establishing very promising Call Center or Business Process Outsourcing (BPO) industries. Many young talents of the Country are already involved in IT related jobs like- Programming, Software development and outsourcing works, and thus the Software industry in Bangladesh has become flourishing with the continuous and restless efforts of the energetic Bangladeshi entrepreneurs within the last few years. Opening and widening up the opportunities with proper Government initiatives and support of the private sector can build a strong IT based infrastructure. The global ICT market has already appraised about the skills and standards of the Bangladeshi talents.  However, all these services and activities related to IT would depend heavily on the internet and International data connectivity.  Presently there are around 120 million mobile phone users and around 44 million Internet users in the country. In addition to usage of mobile phones for voice calls, there is a substantial increase in internet usage through mobile communications in rural and urban areas. ICT and Telecommunication services are getting increasingly popular to the people because these sectors have contributed much in changing their economic condition to a higher level. It is because of the Submarine Cable, that various service providers such as IIG, IGW, BWA, etc. have been benefitted and Internet traffic for both Voice and Data has increased exponentially in Telecommunication industry of Bangladesh. With the efficient and effective utilization of the enormous potentials of the Submarine Cable, the Telecommunications and ICT sector promises a significant contribution to the economy of Bangladesh to boost the nation into a middle income country soon.

Role of the Submarine Cable in Expansion of Broadband Internet in Bangladesh

In the past, before the submarine cable era started in Bangladesh, the long distance telecommunication of Bangladesh was dependent on Satellite systems with severe limitation of bandwidth and speed of communication. We have become aware now that the availability of Internet with high magnitude of bandwidth has great impact on the economic development of the country. Becoming a member of South East Asia- Middle East-Western Europe-4 (SEA-ME-WE-4) consortium, Bangladesh received initial capacity of 7.5 Gbps. Presently, capacity of Bangladesh in SEA-ME-WE-4 submarine Cable System of BSCCL is around 200 Gbps. In recent years, as a result of connecting with submarine cable system there were rapid expansions of the broadband internet industry, resulting in over 180 registered ISP's by 2005 and the number of Internet subscriptions grew from 186,000 in 2000 to 617,300 in 2009. According to official reports, in Bangladesh the total number of Internet Subscribers has reached 36.25 million at the end of August 2013 which is around 23% of the total population.  

The Submarine Cable under BSCCL could provide services to the subscribers at much cheaper price than others as BSCCL would be able to connect many international IP transit points with its own submarine cable system. Bangladesh would expect good revenue earnings by introducing licenses for these services. As a result of connecting with the submarine cable system there were rapid expansions of the broadband internet industry. Keeping the “Vision 2021, Digital Bangladesh” in view, the Government of Bangladesh has exclusive plans to extend the broadband internet and telecommunication facilities for the benefits of the people as elaborated in Government’s ILDTS (International Long Distance Telecommunication Service), Broadband and ICT Policies: the Broadband Penetration rate required to be pulled up from 7% (2011) to 30% within year 2015, by 2015, all the union councils are needed to be under the broadband network, by 2013, about 1.7 million educational institutions (schools and colleges) were supposed to be provided with broadband connections, etc. Already the DCs (District Commissioners) and ADCs are connected; and 1000 Union Councils would be connected through optical fibers and fiber optic connectivity will reach Upazilla Health Centers to provide access to information, video conferencing, telemedicine, etc. The Government has formulated the new standard of Broadband and the bandwidth has to be at least 5 Mbps to meet that standard. To implement the policies and the Vision 2021, a large amount of bandwidth needs to be made available to the Government which will be provided by the Submarine Cable.

After catering for the needs for bandwidth inside the country, Bangladesh has still got opportunities to lease out submarine cable bandwidth to land locked neighboring countries like Nepal and Bhutan. BSCCL is presently working to design for links to Indian North-Eastern provinces for transport of IP transit as below;

(a)  Cox’s Bazar – Chittagong – Comilla – B. baria – Akhaura – Agortola
(b) Cox’s Bazar – Chittagong – Comilla – B. baria – Sylhet – Tamabil – Shilong (Meghalaya).

There is a demand of BSCCL bandwidth in Myanmar also. If BSCCL could be involved to tap the Telecom requirements of those parts of the Globe, it could earn a good deal of foreign currency during the life-times of the submarine cables.

Principal products and services of BSCCL

Bangladesh Submarine Cable Company Limited (BSCCL) is an International Long Distance Communications and International Internet Gateway (IIG) operator that provides various Telecommunications services through the Submarine Cable network.


BSCCL has a Submarine Cable Landing Station located at Jhilongja, Cox’s Bazar from where Backhaul Service Providers are connected. Clients can connect their fiber optic cable for IPLC (International Private Leased Circuits) service from co-location centers (Presently at Chittagong, Mohakhali/Dhaka and Moghbazar) of Backhaul Service Providers. Moreover, with a view to provide multiple options for backhaul connectivity, a co-location centre has been established in Cox's bazar landing station. BSCCL's valued clients can choose their backhaul providers who could directly connect their fibers at the co-location centers of BSCCL. BSCCL is the root service provider of submarine cable bandwidth and handles country’s only submarine cable. Presently, BSCCL is providing the following services:

  • Bandwidth service for different routes and different levels such as STM-1, STM-4, STM-16 to the International Internet Gateway (IIG) companies through International Private Leased Circuits (IPLC).
  • Bandwidth service for different routes and different levels such as STM-1, STM-4, STM-16 to the International (Voice) Gateway (IGW) companies.
  • IP Transit Services to IIG companies
  • IPLC services to any Corporate Customers as per the approval of telecommunications regulatory body of Bangladesh.
  • IIG (International Internet Gateway) which should help the people to get broadband Internet with cheaper rate and better quality of service.


Presently, the Company offers the following products:

  1. IPLC (International Private Leased Circuit) for IIG
  2. IPLC (International Private Leased Circuit) for IGW
  3. IPLC (International Private Leased Circuit) with IP Transit for IIG
  4. IIG (International Internet Gateway) Services for ISP
  5. Dedicated Leased Circuits for Corporate Clients
An International Private Leased Circuit (IPLC) is a dedicated end-to-end connectivity between any two points of locations. It is suitable for IIG, IGW and also for International & National Organizations/Corporations (who require reliable & secure links with committed bandwidth for data/voice/video/internet communications between their offices).
Key Benefits of BSCCL’s IPLC and Internet Gateway services are the following:

1)      High Bandwidth Dedicated Full Duplex Digital Communication
2)      Private, Reliable & Secure
3)      Fast, Efficient & Error free
4)      Global Reach through India, Malaysia, Singapore, Middle East & Europe.
5)      One Stop Shopping Facilities
6)      24 x 7 Tech Support
7)      Constant exchange of Data, Voice, Video, etc. in large volumes & in various formats between multiple destinations.

Joining with the Second Submarine Cable

Existing SMW-4 cable is the only submarine cable that has kept Bangladesh connected with the international information superhighway. Due to any calamity or other reasons, if this cable gets into any kind of physical damage or disruption, country’s international long distance telecommunication would suffer badly. That’s why Bangladesh has been working for long to achieve redundancy for the existing SEA-ME-WE-4 (SMW-4) Submarine Cable as it is a necessity for the country to support for Internet and voice traffic during outage in the SMW-4 cable.

The new SEA-ME-WE-5 (SMW-5) cable will be another submarine cable connecting South East Asia with Western Europe through Middle East and Africa. The cable would also be extended to Hong Kong and Japan. Bangladesh will join as a branch party to this submarine cable. BSCCL worked with the SMW-5 Consortium for implementation of a Branch Sharing arrangement with Myanmar through the “Branch on Branch” architecture, which has helped Bangladesh to reduce the cost in a significant way.

SMW-5 Submarine Cable System will be a 100G DWDM based 20,000 Km long repeatered system that is planned to connect eighteen (18) landing stations. The system will be built with three (3) fiber pairs having 80 λ/fiber-pair (λ, pronounced as “lambda”, is the Greek letter for wavelength of Light), so 80 x 100 Gbps = 8 (eight) Terabits per second capacity for each fiber pair; thus providing a very high design capacity of 24 Terabits per second.

The technology that made this 100 G transmission possible is Polarization Multiplexed QPSK modulation (PM-QPSK) with a coherent receiver. Modulation is required to ensure propagation, to perform multiple accesses and to enhance the SNR, as well as to achieve bandwidth compression. PM-QPSK modulation technique would decrease the baud or symbol rate of the system, using four bits per symbol, keeping the optical spectrum four times narrower than the unreduced baud rate. Because of the capability to pass through multiple Optical Add-Drop Multiplexers (OADMs) and its practical PMD (Polarization Mode Dispersion) tolerance, PM-QPSK is recognized as a viable format for deployment within 50GHz-spaced systems.

Alcatel-Lucent of France and NEC of Japan have been selected for jointly work on building the system.  Both suppliers will use their latest high performance equipments, cable and systems using efficient DWDM, Polarization Division Multiplexed Digital Phase Modulation/Quadrature Phase Shift Keying (PDM-QPSK or DP-QPSK) and Coherent detection technologies, with highly flexible ROADMs (Reconfigurable Optical Add-Drop Multiplexer) along the links.

The Submarine Line Terminal Equipments (SLTEs) will handle very high speed traffic transported to a long distance; and the system will be extremely reliable with sufficient protection schemes and high speed automatic protection switching.

Advantages of joining the SMW-5 Consortium

Joining the SMW-5 cable consortium is expected to bring about a number of benefits for both BSCCL as a submarine cable company, and Bangladesh, as a country. Some of those benefits are described below:

(i) For extending the voice traffic to different parts of the World particularly Middle East, Europe and America, Bangladesh can have chances to reach these destinations almost without any extra charges.

(ii) For IP Transit, Bangladesh would have multi-choices to bring IP bandwidth at a cheaper rate covering both east & west side destinations. This means that BSCCL shall have better opportunity to arrange its traffic (IP) from cheaper destinations of East & West.


(iii) Bangladesh as a country would enjoy the total benefit of redundancy of the circuits & also the multiple destinations for SMW-5.

(iv)  The unit cost for bandwidth would be much cheaper in case of SMW-5 cable. Moreover, the adaptation of future technology for future expansion can be easy approachable.

(v)   There would be a very good opportunity to flourish BPO industries (Call centers, data entry, Software export etc) in Bangladesh with the support of two submarine cable communication systems.

An additional plan has also been made by BSCCL to interconnect the two submarine cable Landing Stations of Bangladesh with a submarine cable. In this way, the two landing stations Cox’s Bazar (for SMW-4) and Kuakata (for SMW-5) will be interlinked. The estimated length of this link is estimated as of the length of 350 Km. It is planned to be made of 2 (two) fiber pairs with an initial capacity of 100 Gbps/per fiber pair and 16 Tbps as design capacity. Other important feature proposed in this submarine cable system is that this would be a repeater less system with a design life of about 25 years. The two submarine cable systems will also be interconnected through a terrestrial DWDM backbone. However, there are vulnerabilities of cable cuts at any location along the route of the terrestrial system, and the interconnection through both the Submarine Cable and Terrestrial System working as a ring will ensure the strong security and redundancy in the Submarine Cable Infrastructure of Bangladesh which will keep the core communication infrastructure seamlessly connected to the Information Superhighway.

Conclusion

The network of submarine or undersea cables around the earth has made today’s broadband internet very fast. It further holds the potential of offering more data transmission capacity.  The global network of today is made of extensive undersea submarine and terrestrial network segments linked together to connect almost all continents of the world. With the development of branching units, more than one destination can be served by a single cable system. Now-a-days, a vast majority of the international traffic is carried by the submarine cables. The reliability of submarine cables is considered high, as multiple paths can be made available in the event of a cable break. Also, the typical information carrying capacity of a single optical fiber in the submarine cables is several terabits per second (Tbps) with such small latencies as just a few milliseconds (ms). It is almost impossible for any other system to match with these submarine cable systems in terms of signal quality, bit-rate (capacity) and latency. Thus, there is a good demand for the optical submarine cable links and these have become national assets to the owner countries.

References

  1. Alcatel: www.alcatel-lucent.com/submarine/
  2. NEC: http://www.nec.com/en/global/prod/nw/submarine/index.html
  3. Optical Internetworking Forum: http://www.oiforum.com/
  4. Telegeography: www.telegeography.com
  5. Suboptic Forum: www.suboptic.org
  6. Infinera: www.infinera.com
  7. Optical Fiber Telecommunications part V- vol. B (Systems and Networks) edited by I. P. Kaminow,T. Li & A. E. Willner
  8. Performance of Dual-Polarization QPSK for Optical Transport Systems by K. Roberts, M. O’Sullivan, K. T. Wu, H. Sun, A. Awadalla, D. J. Krause, & C. Laperle
  9. Latest Technology of Optical Transmission System (40G/100G Solutions) Deployed in SMW-4 Submarine Cable Upgrade and the Bandwidth Situation in Bangladesh by Md. Monwar Hossain & Parvez M. Ashraf (published in Teletech 2011)
  10. Dense Wavelength Division Multiplexing (100 G Solution) adopted in SMW-5 Submarine Cable System - What is in the Laboratory for Higher Bandwidth Solution? by Md. Monwar Hossain & Parvez M. Ashraf (published in Teletech 2012)
  11. Use of Advanced Optical Transmission Technologies for Redundancy in the Submarine Cable Systems of Bangladesh by Md. Monwar Hossain & Parvez M. Ashraf (published in Teletech 2013)
  12. Joining Bangladesh with the Second Submarine Cable (SEA-ME-WE-5) by Md. Monwar Hossain & Parvez M. Ashraf (published in Teletech 2014)
  13. Acknowledgment: Mr. Md. Zakirul Alam, DGM (Development), BSCCL for Information & diagrams on SMW-5 Project & Mr. Abdul Wahhab, DGM (IIG), BSCCL for the Information & diagrams on IIG and IP Transit Setups.
________________________________________________________________________

Md. Monwar Hossain: Managing Director, BSCCL
Parvez M. Ashraf: Deputy General Manager (Bandwidth Planning), BSCCL

Sunday, May 26, 2013

Introduction to Internet Protocol


Md. Bahadur Ali
Member (Finance), BTCL
IPv4 Address Space
IPv4 is based on a 32-bit address scheme that could in theory enable a total of 4 billion hosts (exactly 4,294,967,296) on the whole Internet. However, this 32-bit scheme was originally divided into five hierarchical classes managed by the Internet Assigned Numbers Authority (IANA). The first three classes (A, B and C) are available as globally unique unicast IP addresses. These classes were assigned to the requesters with a fixed length using different network values. A netmask is consecutive series of bits preset to 1 designed to “mask” the network part of an IP address.

Table 1 shows the five classes of IPv4 address, along with their associated ranges and network masks.

Table 1           Hierarchical Classes of IPv4 Address
Classes
Ranges
Netmask
A
0.0.0.0         to    127.255.255.255
255.0.0.0
B
128.0.0.0     to    191.255.255.255
255.255.0.0
C
192.0.0.0     to    223.255.255.255
255.255.255.0
D
224.0.0.0     to    239.255.255.255
-
E
240.0.0.0     to    255.255.255.255
-

Early adopters of the Internet were significant in the 1980s, almost all universities and large corporations received Class A or B addresses, even if they had a small number of computers. Today, these same organizations still have unused IPv4 addresses in their assigned blocks of IPv4 addresses, but they have not redistributed them to other organizations. Moreover, many organizations and companies that received an IPv4 address in the 1980s don’t exist as such anymore.


Larger Address Space
            IPv6 increases by a factor of 4 the number of address bits, from 32 to 128 bits. During the IPv6 design specification, there was a debate about using fixed-length 64-bit addresses versus variable-length addresses up to 160-bit.

Finally, using fixed-length addresses of 128-bits for IPv6 was found to be the most appropriate choice.

With IPv4, the number of addressable nodes is 4,294,967,296 (232), which represents about two IPv4 addresses for every three people. By comparison, the 128-bit length of IPv6 represents 3.4 * 1038 address, which allows approximately 4.8 * 1028 IPv6 addresses for every person in the world.


IP Header
            The IPv4 header describes the fields and compares them to the fields in the IPv6 header.


IPv4 Header Format
            IP packets are carried over link-layer technologies such as Ethernet (10 Mbps), Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps), Frame Relay, and many others. Each link-layer technology family has its own link-layer frame that caries IP packets. An IP packet has two fundamental components:

Ø         IP header – The IP header contains many fields that are used by routers to forward the packet from network to network to a final destination. Fields within the IP header identify the sender, receiver, and transport protocol and define many other parameters.

Ø         Payload – Represents the information (data) to be delivered to the receiver by the sender.

Figure 1          Fields in the IPv4 Header

32 bit
Ver (4
)
Hd Len (4)
Type of Service (8)
Total Length (16)
identification (16)
Flags (3)

20
octets
 
Fragment Offset (13)
Time to Live (8)
Protocol Number (8)
Header Checksum (16)
Source IPv4 Address (32 Bit)
Destination IPv4 Address (32 Bit)

+ (When Necessary)
Options
(Variable)
Padding
(Variable)
        Payload


Following are the IPv4 header fields:
Ø         Version (4-bit) – The version of the IP (Internet Protocol) header. The current IP version used on the Internet is 4 (IPv4). This field contains the value 4.

Ø         Header Length (4-bit) – The length in octets of the header size up to the Payload field. The basic IPv4 header is only 20 bytes long.

Ø         Type of Service (TOS) (8-bit) – Specifies the treatment of the datagram during its transmission through the routers. This field can also be interpreted as Differentiated Services Code Point (DSCP).

Ø         Total Length (16-bit) – The size of the IP packet in octets, including the header and the payload. This field is 16-bit, which means that the maximum size of an IPv4 packet is 65,535 octets.

Ø         Identification (16-bit), Flags (3-bit) and Fragment Offset (13-bit) – Fields related to packet fragmentation by routers when the Maximum Transmission Unit (MTU) along a path is smaller than the sender’s MTU. The MTU is the maximum size in octets of an IP packet that can be transmitted on a specific communication medium, such as Ethernet, Fast Ethernet, and so on. For Ethernet, the MTU is 1500 octets.

Ø         Time to Live (8-bit) – This field is decremented each time the packet passes through an intermediary router. When this field contains the value 0, the packet is destroyed, and an Internet Control Message Protocol for IPv4 (ICMPv4) Type 11 error message (Time Exceeded) is sent to the source node.

Ø         Protocol Number (8-bit) – Specifies the upper-layer protocol used in a packet’s payload, such as Transport Control Protocol (TCP), User Datagram Protocol (UDP), Internet Control Message Protocol (ICMP), or any others. Protocols supported are defined by the Internet Assigned Numbers Authority (IANA).

Ø         Header Checksum (16-bit) – Represents the checksum of the IP header and is used for error checking. This field is verified and recomputed by each intermediary router along a path.

Ø         Source IPv4 Address (32-bit) – The sender’s IPv4 address.

Ø         Destination IPv4 Address (32-bit) – The receiver’s IPv4 address.

Ø         Options (variable) – This optional field might appear in an IPv4 packet. The Options field is variable in size and increases the length of the header when used.

Ø         Padding (variable) – Padding is used to ensure that the packet ends on a 32-bit boundary. It also increases the header’s size.

Ø         Payload (variable) – The payload is not a field of the basic IPv4 header. Rather, it represents the data to be delivered to a destination address. The payload includes an upper-layer header.


Basic IPv6 Header Format
The basic IPv6 header contains eight fields, in comparison with 12 fields in IPv4 (without the Options and Padding fields), for a total length of 40 octets. Moreover, the basic IPv6 header might have one too many extension headers daisy-chained following the 40 octets.

The IPv6 protocol represents an upgrade of the IPv4 protocol. The fields in the basic IPv6 heade
r are:

Ø  
       Version (4-bit) – The IP version. This field contains the value 6 rather than the value 4 contained in an IPv4 packet.

Ø         Traffic Class (8-bit) – This field and its functions are similar to the Type of Service field in IPv4. This field tags an IPv6 packet with a Differentiated Services Code Point (DSCP)  that specifies how the packet should be handled.

Ø         Flow Label (20-bit) – This field is used to tag a flow for IPv6 packets. This is new in the IPv6 protocol. The current IETF standard does not specify the details about how to manage and process the Flow Label.

Ø         Payload Length (16-bit) – This field represents the payload’s length. The payload is the remaining part of the packet following the IPv6 header.

Ø         Next Header (8-bit) – This field defines the type of information following the basic IPv6 header. The type of information can be an upper-layer protocol.

Ø         Hop Limit (8-bit) – This field defines the maximum number of hops (intermediate routers) that the IP packet can pass through. Each hop decreases this value by 1.

Ø         Source Address (128-bit) – This field identifies the IPv6 source address of the sender.

Ø         Destination Address (128-bit) – This field identifies the packet’s IPv6 destination address.

Figure 2          Fields Within the Basic IPv6 Header:

32 bit
Version (4)
Traffic Class (8)
Flow Label (
20)
Payload Length (16)
Next Header (8)
Hop Limit (8)

40
octets
 
Source IPv6 Address (128-Bit)


Destination IPv6 Address (128 Bit)


Variable Length
 
Next Header
Extension Header Information

   Payload







                        Table 2 compares IPv4 and IPv6 headers.
Table 2           Comparison of IPv4 and IPv6 Headers.

Fields of the IPv4 Header
Fields of the IPv6 Header
Comparison of IPv4 and IPv6 Headers
Version (4-bit)
Version (4-bit)
Same function but the IPv6 header contains a new value.
Header Length (4-bit)
-
Removed in IPv6. The basic IPv6 header always has 40
octets.
Type of service (8-bit)
Traffic class (8-bit)
Same function for both headers.
-
Flow label (20-bit)
New field added to tag a flow for IPv6 packets.
Total length (16-bit)
Payload length (16-bit)
Same function for both headers.
Identification (16-bit)
-
Removed in IPv6 because fragmentation is handled differently in IPv6.
Flags (3-bit)
-
Removed in IPv6 because fragmentation is handled differently in IPv6.
Fragment offset (13-bit)
-
Removed in IPv6 because fragmentation is handled differently in IPv6.
Time to live (8-bit)
Hop limit (8-bit)
Same function for both headers.
Protocol number (8-bit)
Next header (8-bit)
Same function for both headers.
Header checksum (16
-bit)
-
Removed in IPv6. Link-layer technologies and upper-layer protocols handle checksum and error control.
Source address (32-bit)
Source address (128-bit)
Source address is expanded in IPv6.
Destination address (32-bit)
Destination address (128-bit)
Destination address is expanded in IPv6.
O
ptions (variable)
-
Removed in IPv6. The way to handle this option in different in IPv4.
Padding (variable)
-
Removed in IPv6. The way to handle this option in different in IPv4.
-
Extension headers
New way in IPv6 to handle Options fields, fragmentation, security, mobility, Loose Source Rouging, Record Route, and so on. The following section presents IPv6’s extension headers.



Some Important Information About IPv6 Addressing


Ø         IPv6 addresses are 128-bit hexadecimal numbers.

Ø         Link local unicast addresses are easy to identify

Ø         Leading zeros are suppressed
.

Ø       
  Inline zeros can sometimes be suppressed.

Ø         Loopback addresses don’t even look like addresses.

Ø         A traditional subnet mask not neede
d.

Ø  
       Domain Name System (DNS) is still a valid technology.

Ø         IPv6 can tunnel its way across IPv4 networks.

Ø         You might already be using IPv6.

Ø         Windows doesn’t fully support IPv6.


References/Sources:
-           Internet
-           Cisco Self Stud
y
Edit
ed by: Regis Desmeules