Link-Level Flow Control

Problem: Transmitting a Packet to a Full Buffer

The Link Layer of each port on a CA, router, or switch implements one or more transmit/receive buffer pairs (referred to as VLs) that are used to transmit and receive data packets. A data packet is defined as any packet other than an SMP or a link-level Flow Control Packet (described in this section).

At a given moment, one or more of a port's data VL transmit buffers may have one or data packets queued up for transmission. Assume that the data VL arbiter (described earlier) has decided that it is a specific data VL's turn to transmit and the arbitration table entry has sufficient Weight left for the packet to be transmitted.

The VL transmit buffer transmits the packet to ...

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