rfc9506v3.txt | rfc9506.txt | |||
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skipping to change at line 1029 ¶ | skipping to change at line 1029 ¶ | |||
The value of the Unreported Loss counter is incremented for every | The value of the Unreported Loss counter is incremented for every | |||
packet that the protocol declares lost, using whatever loss detection | packet that the protocol declares lost, using whatever loss detection | |||
machinery the protocol employs. If the protocol is able to rescind | machinery the protocol employs. If the protocol is able to rescind | |||
the loss determination later, a positive Unreported Loss counter may | the loss determination later, a positive Unreported Loss counter may | |||
be decremented due to the rescission. In general, it should not | be decremented due to the rescission. In general, it should not | |||
become negative due to the rescission, but it can happen in few | become negative due to the rescission, but it can happen in few | |||
cases. | cases. | |||
This loss signaling is similar to loss signaling in [ConEx], except | This loss signaling is similar to loss signaling in [ConEx], except | |||
that the Loss Event bit is reporting the exact number of lost | that the Loss Event bit is reporting the exact number of lost | |||
packets, whereas the signal mechanism in in [ConEx] is reporting an | packets, whereas the signal mechanism in [ConEx] is reporting an | |||
approximate number of lost bytes. | approximate number of lost bytes. | |||
For protocols, such as TCP [TCP], that allow network devices to | For protocols, such as TCP [TCP], that allow network devices to | |||
change data segmentation, it is possible that only a part of the | change data segmentation, it is possible that only a part of the | |||
packet is lost. In these cases, the sender must increment the | packet is lost. In these cases, the sender must increment the | |||
Unreported Loss counter by the fraction of the packet data lost (so | Unreported Loss counter by the fraction of the packet data lost (so | |||
the Unreported Loss counter may become negative when a packet with | the Unreported Loss counter may become negative when a packet with | |||
L=1 is sent after a partial packet has been lost). | L=1 is sent after a partial packet has been lost). | |||
Observation points can estimate the end-to-end loss, as determined by | Observation points can estimate the end-to-end loss, as determined by | |||
skipping to change at line 1185 ¶ | skipping to change at line 1185 ¶ | |||
them is called "Reflection Block" (Reflection Block). | them is called "Reflection Block" (Reflection Block). | |||
The M value is then updated every time a completed Q Block in the | The M value is then updated every time a completed Q Block in the | |||
incoming square signal is received, following this formula: | incoming square signal is received, following this formula: | |||
M=round(avg(p)). | M=round(avg(p)). | |||
The parameter avg(p), the average number of packets in a marking | The parameter avg(p), the average number of packets in a marking | |||
period, is computed based on all the Q Blocks received since the | period, is computed based on all the Q Blocks received since the | |||
beginning of the current Reflection Block. | beginning of the current Reflection Block. | |||
The transmission of an Reflection Block is considered complete (and | The transmission of a Reflection Block is considered complete (and | |||
the signal toggled) when the number of packets transmitted in that | the signal toggled) when the number of packets transmitted in that | |||
block is at least the latest computed M value. | block is at least the latest computed M value. | |||
To ensure a proper computation of the M value, endpoints implementing | To ensure a proper computation of the M value, endpoints implementing | |||
the R bit must identify the boundaries of incoming Q Blocks. The | the R bit must identify the boundaries of incoming Q Blocks. The | |||
same approach described in Section 3.2.3 should be used. | same approach described in Section 3.2.3 should be used. | |||
By looking at the R bit, unidirectional observation points have an | By looking at the R bit, unidirectional observation points have an | |||
indication of loss experienced by the entire unobserved channel plus | indication of loss experienced by the entire unobserved channel plus | |||
the loss on the path from the sender to them. | the loss on the path from the sender to them. | |||
End of changes. 2 change blocks. | ||||
2 lines changed or deleted | 2 lines changed or added | |||
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