The role is to transfer frames to packets
Damaged frames are discarded. Retransmission - if needed - is handled by higher-layer protocols, like TCP.
Network Layer This layer addresses the data. It adds an IP address which allows our data to flow across networks. The protocols involved in this layer are IP and IPX. Data Link Layer This layer provides the functional and procedural means to transfer data. It also corrects any errors that may occur in the Physical layer. The protocols used at this layer are media access control and logical link control.
Elementary data link protocols must agree at the most rudimentary level. The data frame must be constructed from this level, and all protocols must agree.
the network layer --> check your question. ^^^^^^^^^^^^^^^^^^^^^^^^^^^ That is totally not the right answer, how about you actually read the book for the course. It is the data link layer that does encapsulation. I agree - its the Data Link Layer which encapsulates the Network layer...NOT the Network Layer.
Data link layer
Data link layer protocols like PPP and HDLC define how data is encapsulated for transmission across a WAN link.
Damaged frames are discarded. Retransmission - if needed - is handled by higher-layer protocols, like TCP.
TELNET
The most common WAN data-link protocols are: 1. HDLC 2. PPP 3. Frame Relay 4. ATM
physical layer.
network data-link
Here's what you should know: Data link layer protocols must be concerned with the rules for transmitting data across the network media, particularly with encoding and carrying "frames" of data. Although this layer includes providing error detection and notification by adding the Cyclic Redundancy Check (CRC), the Transport Layer is primarily responsible for end-to-end error-free message delivery. WAN Data-Link protocols primarily define how data frames should be packaged for different types of networks. To quote: The data link protocols available for WAN communications define how networks will carry the data frames on a given data link. The data link protocols used for WANs come in three categories: 1. Interface to IBM enterprise data centers: SDLC 2. WAN connections using peer devices: HDLC & PPP 3. Switched or relayed services: X.25/LAPB, Frame Relay, ISDN/LAPD, ATM. Some of these protocols provide functionality as high as in the Network layer of the OSI, and all of these protocols transfer data over a WAN data link.
Network Layer This layer addresses the data. It adds an IP address which allows our data to flow across networks. The protocols involved in this layer are IP and IPX. Data Link Layer This layer provides the functional and procedural means to transfer data. It also corrects any errors that may occur in the Physical layer. The protocols used at this layer are media access control and logical link control.
Atm frame relay
atm and frame-relay
The Internet protocol stack, often referred to as the TCP/IP model, consists of five layers: the application layer, transport layer, internet layer, link layer, and physical layer. The application layer handles high-level protocols and user interfaces, while the transport layer ensures reliable data transfer between hosts. The internet layer is responsible for routing packets across networks, and the link layer manages the physical transmission of data over network interfaces. The physical layer deals with the actual hardware and transmission mediums used to transmit data.
The data link layer is still needed for flow control over the transmission channel and for framing the data. In a multiple access medium such as a LAN, the data link layer is required to coordinate access to the shared medium among the multiple users.