Requested revision
Standard: | 802.1CB-2017 | Clause: | 7.4.3 |
Clause title: | Base recovery function |
Rationale for revision
The conclusion on duplicate delivery at the end of the paragraph above NOTE 1 is wrong. Section "7.4.3 Base recovery function" describes the relationship of the (1) size of SequenceHistory variable and (2) the difference in the number of packets in flight on all paths. It is fine, if the "receive window" covered by SequenceHistory is too small, then packets on the long path are not considered (discarded) by the elimination function. Later in section "7.4.3.4 VectorRecoveryAlgorithm" such discards are stated explicitly: ... "Rogue" packets, meaning packets outside the frerSeqRcvyHistoryLength window, are discarded as invalid ...
However, the text in 7.4.3 makes a wrong conclusion as it says that duplicate delivery occurs. It is stated both in NOTE 1 in 7.4.3 and in the paragraph right above NOTE 1.
Proposed text
Action-1: Change the text to "... can be delivered out-of-order. If the
difference exceeds this value, then packets can be discarded."
Action-2: Change text in NOTE 1: "... in Bulk Streams. If the actual path difference in a given network exceeds the capability of a sequence recovery function, then packets will be discarded."
Impact on existing networks
None. When base recovery implemented, it does not create duplicates. It is just "understood" by those that worked on the standard.
Originator
Name: | Balázs Varga | Email: | balazs.a.varga@ericsson.com<mailto:balazs.a.varga@ericsson.com> |
Affiliation: | Ericsson | ||
Submitted: | 2020-03-02 |