What is the Difference Between HDLC and PPP?
🆚 Go to Comparative Table 🆚HDLC and PPP are both data link layer protocols used for data communication between network devices, but they differ in several key aspects:
- Orientation: HDLC is a bit-oriented protocol, while PPP is a byte-oriented protocol.
- Connection Type: HDLC is implemented by point-to-point link configuration and multi-point, while PPP is implemented by point-to-point configuration only.
- Media Type: HDLC can only handle synchronous media, while PPP can handle both synchronous and asynchronous media.
- Authentication: HDLC does not support authentication, while PPP supports authentication protocols like PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol).
- Link Quality: HDLC does not offer quality checking of established links, while PPP offers quality checking of established links using LCP (Link Control Protocol).
- Error Detection and Correction: Both protocols use CRC (Cyclic Redundancy Check) for error detection, but HDLC does not provide built-in error correction components. PPP, on the other hand, uses LCP to negotiate parameters and handle errors.
- Multilink Support: PPP supports multilink connections, allowing multiple physical connections to be combined to increase data transmission rate.
- Cost: HDLC is generally more costly than PPP.
In summary, HDLC and PPP are both data link layer protocols used for data communication, but they differ in their orientation, connection type, media handling, authentication, link quality, error detection and correction, and support for multilink connections.
Comparative Table: HDLC vs PPP
Here is a table comparing the differences between HDLC and PPP:
| Parameter | HDLC | PPP |
|---|---|---|
| Protocol Type | Bit-oriented | Byte-oriented |
| Implementation | Point-to-point and multi-point | Point-to-point only |
| Layer | Data Link (Layer 2) | Data Link and Network (Layer 2 and Layer 3) |
| Dynamic Addressing | Not offered | Offered |
| Authentication | None | Provides Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP) |
| Error Detection | Uses Cyclic Redundancy Check (CRC) for error detection | Includes error detection and correction mechanisms |
| Efficiency | Uses efficient bandwidth utilization techniques, such as sliding windows | Supports full-duplex communication and bandwidth optimization techniques, such as sliding windows |
HDLC (High-Level Data Link Control) is a bit-oriented protocol that works at the Data Link Layer (Layer 2) and supports both connection-oriented and connectionless services. It is implemented by point-to-point and multi-point links and supports half-duplex and full-duplex transmission.
Point-to-Point Protocol (PPP) is a byte-oriented protocol that works at both the Data Link Layer (Layer 2) and the Network Layer (Layer 3). It is implemented by point-to-point configuration only and supports dynamic addressing and authentication mechanisms such as Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP).
Both protocols support error detection and correction mechanisms, full-duplex communication, and bandwidth optimization techniques, such as sliding windows.