Buffer Credits

Buffer credits are also buffer -to -buffer credits called. They ensure communication in a Fibre Channel Storage Area Network ( SAN), especially for large distances between the devices. However, the number of buffer credits required depends not only on the distance. The transmission rate of the Fibre Channel cable also plays a role.

Because the signals can not run faster than the speed of light, but each arrived packet must be confirmed at the receiver side with an ACK, a number of packets is agreed between the two endpoints, which can be found in the input buffer space. This allows the sending device to send this number of data packets without waiting for confirmation for each package.

The sending device keeps a record of the number of data packets in transit, ie those that have been submitted, the acknowledgment of receipt is not returned yet. The " buffer credits " are reduced for each data packet sent by one, incremented for each data packet confirmed by one. Are the " buffer credits " arrived at zero, the transmission is interrupted until the arrival of acknowledgments.

• Computer Networks
• Memory technology