On 20th November 2024, IEEE BRAC University Communications Society Student Branch Chapter organized an industrial visit to the Bangladesh Telecommunications Company Limited (BTCL) main  office in Dhaka. This trip was part of the chapter’s initiative to connect academic learning with real world industry exposure. The visit provided students with a firsthand look at BTCL’s operations, including key aspects of telecommunications infrastructure such as fiber optic systems, network switching, and data transmission technologies. With guidance from faculty advisors Tasfin Mahmud and Atib Mohammad Oni, 15 students explored how BTCL supports communication services nationwide.

BTCL, as Bangladesh’s primary national telecom provider, plays a critical role in the country’s digital connectivity by offering a range of services, from telephony to broadband internet. Established from the former Bangladesh Telegraph and Telephone Board (BTTB) in 2008, BTCL has grown alongside advances in technology, including fiber optics and high speed internet infrastructure. Its nationwide network is crucial in connecting rural and urban areas and providing reliable communication support during emergencies. This visit enriched students’ understanding of how BTCL’s vast network underpins the country’s telecommunications framework, bringing their theoretical studies to life with real-world applications.

Upon arrival, students and faculty were directed to the lecture theater, where they settled in for a session led by MD Golam Mostafa, the General Manager, Switching and Exchanges Department, BTCL. He provided an insightful overview of BTCL’s telephony operations, highlighting the protocols in place, such as fuses and circuit breakers, to ensure safe and efficient service. He explained the three main types of signaling—CAS, CCS, and No.7—mentioning that BTCL currently uses the No.7 signaling method. He also explained how local and international calls are made. To conclude, he introduced the “Alap” app, which offers an affordable rate of just 40 paisa  plus 15% VAT (totaling 46 poysha), making it a highly user friendly option.

After a short break, Mr. Mostafa Al Mohammad, Deputy General Manager, International Internet Gateway (IIG), BTCL, led an interactive discussion with the students, providing insights into BTCL’s internet infrastructure. He explained that BTCL’s International Internet Gateway (IIG) connects to submarine cables (SMW) in Chattogram and Moghbazar, as well as International Terrestrial Cable (ITC) facilities in Jessore and Moghbazar. He also detailed how BTCL supplies IP bandwidth through direct connections for essential locations, such as libraries and outsourcing centers. Additionally, he highlighted BTCL’s cache servers for platforms like Facebook, TikTok, Instagram, and Bingo, which help reduce network delays. With BTCL’s fiber optic network now extending to 490 upazilas, users benefit from comprehensive access to internet services, and voice and data are seamlessly transmitted through GPON technology. The discussion also covered domain management, where Mr. Mohammad explained how human-readable addresses are converted to IP addresses and introduced the use of Internationalized Domain Names (IDNs), both facilitated by BTCL. This interactive session allowed students to gain a deeper understanding of BTCL’s role in digital connectivity across the nation.

Following the interactive discussion, students were divided into two groups, each accompanied by a faculty member. One group had the opportunity to visit the server room, where telephone communications are managed and this group was led by Md. Rayhan Kabir. The students were especially fortunate to witness the high security servers responsible for handling calls for the Prime Minister, the President, and other sensitive connections which is also known as “Red Telephone”. During the tour, they observed the servers supporting the GPON system, the Access Gateway (AGW) which is the starting point for data transmission that flows to distribution points as well as the AAA security system, which safeguards users from potential threats. They also saw the BRAS server, which supplies internet connectivity to the GPON router, and the routers linked to the ICX, responsible for call management.

The other group was taken to a separate server room dedicated to internet operations. Their visit began with a briefing on the fundamentals of internet functionality, highlighting how most systems run on optical networks and providing insights into various bandwidth providers besides BTCL. They learned that BTCL boasts the most interconnected infrastructure among them. Inside the server room, the students observed the complex setup, with cables routed beneath the raised flooring. They were shown the main server rack, with connections of 400 Gbps and 100 Kbps, supporting nearly a million connections. Additionally, they had the chance to speak with a representative from ZTE and took photos to capture the experience.

At the end of the visit, Tasfin Mahmud, the advisor of the IEEE BRAC University Communications Society Student Branch Chapter, presented a crest to Mr. Mostafa Al Mohammad (DGM) in appreciation of his support. The event concluded with a group photo, followed by a heartfelt thank you speech acknowledging Mr. Mohammad for taking time from his busy schedule to guide and engage with the students throughout the visit. Feedback from the students indicated that they left feeling satisfied, having had the rare chance to see the intricate operations of BTCL up close, an experience that brought their academic knowledge to life and provided valuable insights into practical applications.