Search results
Results from the WOW.Com Content Network
Selective Repeat is part of the automatic repeat request (ARQ). With selective repeat, the sender sends a number of frames specified by a window size even without the need to wait for individual ACK from the receiver as in Go-Back-N ARQ. The receiver may selectively reject a single frame, which may be retransmitted alone; this contrasts with ...
Go-Back-N ARQ is a specific instance of the automatic repeat request (ARQ) protocol, in which the sending process continues to send a number of frames specified by a window size even without receiving an acknowledgement (ACK) packet from the receiver.
Variations of ARQ protocols include Stop-and-wait ARQ, Go-Back-N ARQ, and Selective Repeat ARQ. All three protocols usually use some form of sliding window protocol to help the sender determine which (if any) packets need to be retransmitted. These protocols reside in the data link or transport layers (layers 2 and 4) of the OSI model.
Three types of ARQ protocols are Stop-and-wait ARQ, Go-Back-N ARQ, and Selective Repeat ARQ. ARQ is appropriate if the communication channel has varying or unknown capacity, such as is the case on the Internet.
Selective repeat is a connection oriented protocol in which both transmitter and receiver have a window of sequence numbers. The protocol has a maximum number of messages that can be sent without acknowledgement. If this window becomes full, the protocol is blocked until an acknowledgement is received for the earliest outstanding message.
After much deliberation, the College Football Playoff committee chose SMU over Alabama for the final spot in the 12-team field. See the full schedule.
For the treatment centers, the revolving door may be financially lucrative. “It’s a service that rewards the failure of the service,” Johnson said. “If you are going to a program, you don’t succeed and you pay X-thousand dollars. When you fail, you go back — another X-thousand dollars. Because it’s your fault.”
The extremely popular HDLC protocol uses a 3-bit sequence number, and has optional provision for selective repeat. However, if selective repeat is to be used, the requirement that n t +n r ≤ 8 must be maintained; if w r is increased to 2, w t must be decreased to 6. Suppose that w r =2, but an unmodified transmitter is used with w t =7, as is ...