BCA 301T Computer Networks Notes for GGSIPU BCA Sem 5

Scheme: BCA (UGC CCFUP) | Applies to: batch admitted 2024-25 onwards | Verified against: BCA scheme and syllabi, 19 Aug 2026

On this page

1. BCA 301T at a glance: credits, units and exam pattern
2. Unit-wise notes
   1. Unit 1: Basic Concepts, OSI and TCP/IP Models, Transmission Media
   2. Unit 2: Telephony (Multiplexing and Switching) and the Data Link Layer
   3. Unit 3: Network Layer, Internetworking, Addressing and Routing
   4. Unit 4: Transport Layer and the Upper Layers of the OSI Model
3. Excerpt from page 31: virtual-circuit and message switching
4. Syllabus coverage map
5. How to write BCA 301T answers
6. Exam corner
7. Who writes and checks these notes
8. BCA 301P lab and other Semester 5 papers
9. FAQs
10. Get the full notes

BCA 301T Computer Networks at a glance: GGSIPU BCA Sem 5 credits, units and exam pattern

BCA 301T is one of two core theory papers in Semester 5, listed with the other GGSIPU BCA Semester 5 papers.

BCA 301T Computer Networks Notes unit-wise: 28 solved examples and 51 diagrams across 4 units

These GGSIPU BCA Sem 5 Computer Networks notes run to 78 pages. Each unit opens with its own cover and a "What you will learn" list, and closes with a quick revision table and exam questions; Units I to III add a formula sheet. Other papers' notes: GGSIPU BCA notes.

BCA 301T Unit 1: Basic Concepts, OSI and TCP/IP Models, Transmission Media

Pages 3 to 24. Data communication, line configuration, topologies and transmission modes come first, then the seven OSI layers and the TCP/IP suite. The last third is numerical: decibels, throughput, propagation and transmission time, wavelength, Nyquist and Shannon. 6 solved examples, 11 figures, 16 two-mark and 9 ten-mark questions.

Quick look: OSI vs TCP/IP (from page 15)

BCA 301T Unit 2: Telephony (Multiplexing and Switching) and the Data Link Layer

Pages 25 to 44, the most numerical unit. FDM, WDM and both kinds of TDM lead into switching. The data link half covers burst errors, byte and bit stuffing, parity, CRC, checksum, the (7, 4) Hamming code and the three ARQ protocols. 11 solved examples, 9 practice numericals with answers, 16 figures, 12 two-mark and 9 ten-mark questions.

Quick look: ARQ window sizes (from page 41)

BCA 301T Unit 3: Network Layer, Internetworking, Addressing and Routing

Pages 45 to 62. Each connecting device is placed at its OSI layer, then IPv4 classes, CIDR, subnetting by subnets or by hosts, and IPv6 abbreviation. Routing covers static versus dynamic routes, Cisco IOS commands, distance vector, link state with Dijkstra, and RIP, OSPF and BGP. 9 solved examples, 11 figures, 12 two-mark and 8 ten-mark questions.

Quick look: 192.168.1.0/24 as four /26 subnets (from page 52)

BCA 301T Unit 4: Transport Layer and the Upper Layers of the OSI Model

Pages 63 to 78. Ports, the UDP header and the TCP segment come first, then connection management, flow, error and congestion control, and a UDP, TCP and SCTP comparison. The session, presentation and application layers end the book, with DNS, HTTP, FTP, e-mail, SSH and DHCP. 2 solved examples, 13 figures, 12 two-mark and 8 ten-mark questions.

Quick look: three-way handshake (from page 69)

1. SYN: client seq = 8000 (uses one sequence number, no data).
2. SYN + ACK: server seq = 15000, ack = 8001, plus its rwnd.
3. ACK: client seq = 8001, ack = 15001.

Virtual-circuit and message switching in data networks: excerpt from page 31 of the BCA 301T notes

Excerpt from page 31

Virtual-circuit networks

The page opens just below the datagram figure (Fig 2.7), where the packets of one message take different routes and may arrive out of order. A virtual-circuit network is a cross between a circuit-switched network and a datagram network, and it borrows features from both.

• As in circuit switching, there are setup and teardown phases in addition to the data transfer phase.
• Resources can be allocated during the setup phase, as in circuit switching, or on demand, as in a datagram network.
• As in a datagram network, data are packetised and each packet carries an address in its header. That address has only local jurisdiction: a short Virtual-Circuit Identifier (VCI) tells the next switch where to send the packet, instead of a full end-to-end address.
• As in circuit switching, all packets follow the same path set up during the connection, so they arrive in order.
• Virtual-circuit switching is normally implemented at the data link layer. Examples are Frame Relay, ATM and X.25.

Fig 2.8 on the same page shows every packet of one message following the same pre-established path through the switches, which is the quickest way to tell it apart from the datagram figure above it.

Message switching

Message switching is a store-and-forward technique. There is no dedicated path between the sender and the receiver, and, unlike packet switching, the message is not divided into packets. The whole message goes from the source to the first node, where it is stored on disk and checked for errors.

When the next link is free, the node forwards the entire message to the next node, and so on until it reaches the destination. Each message carries the destination address. The method was used in telegraph networks and early e-mail systems. Packet switching has replaced it, but the store-and-forward idea still lives on in e-mail.

Do the BCA 301T notes cover the full GGSIPU syllabus?

Yes. Every topic in the four official BCA 301T units has a section in the notes; our unit check found no gaps.

Official source: BCA Scheme of Examination and Syllabi, batch 2024-25 onwards.

Every course in GGSIPU notes gets this same unit check, so a missing topic is named, never hidden.

How to write BCA 301T answers: formula-first numericals, ARQ timelines and six-point comparison tables

BCA 301T answers fall into three types, and the notes coach each in their exam-tip boxes. Numericals (decibels, Shannon, subnetting, CRC, Hamming) earn step marks. Process answers (ARQ, the TCP handshake, routing) earn marks for the diagram. Comparisons (OSI vs TCP/IP, guided vs unguided, circuit vs packet switching) earn marks for structure.

For numericals the rule is: write the formula, substitute values with units, then box the answer, because step marks survive an arithmetic slip. The slip the notes flag most is putting a dB value straight into Shannon's formula.

Worked example: Shannon capacity with SNR in dB

1. Bandwidth B = 2 MHz, SNR_dB = 36.
2. Convert first: SNR = 10^3.6 ≈ 3981.
3. C = B × log₂(1 + SNR) = 2 × 10⁶ × log₂(3982) ≈ 2 × 10⁶ × 11.96.
4. C ≈ 23.9 Mbps. Using 36 instead of 3981 gives a wrong answer.

For ARQ, draw the sender and receiver timeline with one lost frame and the time-out, and state the windows: 1 for Stop-and-Wait, 2^m − 1 for Go-Back-N, 2^m−1 for Selective Repeat. On the handshake diagram, fill in real sequence and acknowledgement numbers, as in the quick look above.

Give each routing protocol four labels: interior or exterior, algorithm, metric and update method. Present subnetting and Dijkstra answers as a table, and every comparison as a table of at least six points.

Topology answers need four parts each: a diagram, advantages, disadvantages and one example, such as an office LAN for star. For the internetworking devices question, draw the devices against the OSI layers first (Fig 3.1); that one figure answers half of it.

Once the format feels natural, try it on the GGSIPU BCA important questions.

BCA 301T exam corner: 52 two-mark and 34 ten-mark exam questions by unit

The BCA 301T notes list 52 two-mark and 34 ten-mark exam-style questions across 4 units, plus 28 solved examples and 9 practice numericals with answers. Four samples:

1. Unit I (2 Marks): Propagation time for 6000 km at 2 × 10⁸ m/s? Pointer: (6 × 10⁶ m) ÷ (2 × 10⁸ m/s) = 0.03 s = 30 ms.
2. Unit II (2 Marks): Hamming distance between 10101 and 11110? Pointer: XOR gives 01011, so the distance is 3.
3. Unit III (2 Marks): First and last address of the block holding 205.16.37.39/28? Pointer: 16 addresses; 39 AND 240 = 32, so 205.16.37.32 to 205.16.37.47.
4. Unit IV (2 Marks): Ranges of well-known, registered and dynamic ports? Pointer: 0 to 1023, 1024 to 49,151, 49,152 to 65,535.

More practice sits in the BCA 301T important questions.

Who writes and checks the BCA 301T CN notes?

• Prateek Talwar, author: Founder, Unnati Educations; Associate Company Secretary (ACS), ICSI, membership no. 58704; B.Com, University of Delhi (SOL), 2012. Profile
• Ritik Rawat, subject reviewer, including the Cisco IOS commands on pages 55 and 56: Senior Full Stack Developer, Unnati Educations; B.Tech. Profile

The 2026-27 edition of the BCA 301T Computer Networks IPU notes follows the scheme for the 2024-25 batch onwards, using the third-year syllabus approved on 19 August 2026. It has four unit covers, three formula sheets and 129 revision-table rows. Last checked on 13 October 2026; see our editorial policy.

The same team builds GGSIPU important questions from these unit question banks.

BCA 301T and the BCA 301P Computer Networks lab, plus other GGSIPU BCA Sem 5 papers

BCA 301P Computer Networks lab notes: 1 credit, 2 practical hours. The official PDF leaves the practical list to the teacher, so we quote no practical count.

Unit III feeds the lab most: its two-router example (pages 55 and 56) sets interface addresses, static routes, RIP v2 and OSPF, then checks them with show ip route.

Other Semester 5 papers: BCA 303T Artificial Intelligence (with BCA 303P); one elective pair from BCA 305T Natural Language Processing, BCA 307T Network Security or BCA 309T Full Stack Development using Java; BCA 311 Summer Training; and BCA 313T Introduction to Management and Entrepreneurship Development or BCA 315T MOOC Course. BCA 307T builds on the Unit IV key-cryptography table and SYN flooding.

BCA 301T CN notes FAQs

What is the passing mark for BCA 301T?

BCA 301T is marked out of 100: 40 internal and 60 end-term. The BCA scheme of examination does not print a pass percentage for this paper; its 40% line is written only for the non-credit Bridge Course in Mathematics. End-term minimums, grading and re-appear rules come from the university's Ordinance 11, which is published on ipu.ac.in.

How is the BCA 301T end-term paper set?

The 60-mark BCA 301T paper opens with a compulsory Question 1: ten short questions of 2 marks, at least two from each unit, for 20 marks. Each unit then has two 10-mark questions and you attempt one per unit, adding 40 marks. Examiners are asked to map every question to the paper's five course outcomes.

Which BCA 301T unit has the most numericals?

Unit II. Its 11 solved examples cover FDM bandwidth, TDM slot timing, byte and bit stuffing, parity, two CRC divisions, checksum, the (7, 4) Hamming code, Stop-and-Wait efficiency and ARQ windows, and page 42 adds 9 practice numericals with answers. Unit III comes next with 9 solved examples, mostly on IPv4 classes, CIDR blocks and subnetting.

Do the BCA 301T notes follow the 2024-25 BCA scheme?

Yes. They follow the four units printed for the batch admitted in 2024-25 onwards, where BCA 301T is a 4-credit core theory paper in Semester 5. We checked them on 13 October 2026 against the version with the third-year syllabus approved on 19 August 2026. Students of an older batch should compare their own syllabus first.

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Unnati Educations is an independent education provider based in Vikaspuri, Delhi. We are not affiliated with, authorised by, or endorsed by Guru Gobind Singh Indraprastha University (GGSIPU). 'GGSIPU' and 'IPU' are used only to describe the syllabus our notes follow. For official information, visit ipu.ac.in.