Ethereal转储中的TSV和TSER字段是什么意思? [英] What is the meaning of the TSV and TSER fields in an Ethereal dump?

问题描述

Ethereal转储中的TSV和TSER字段是什么意思?我尝试使用Google搜索，但找不到答案.

What is the meaning of the TSV and TSER fields in an Ethereal dump? I tried googling but could not find the answer.

推荐答案

TSV是时间戳值字段.它与序列号结合使用，以唯一地标识片段(因为序列号可能会换行).

TSV is the Timestamp Value field. It is used in conjunction with sequence number to uniquely identify segments (since sequence numbers may wrap).

TSER是 Timestamp Echo Reply 字段.这在ACK消息中使用.它保存了最后收到的TSV值的副本.可用于往返时间估计(RTT =当前时间-TSER).

TSER is the Timestamp Echo Reply field. This is used in ACK messages. It holds a copy of the last TSV value received. It can be used for round trip time estimation (RTT = current time - TSER).

RFC 1323(高性能TCP扩展):

  TCP Timestamps Option (TSopt):

     Kind: 8

     Length: 10 bytes

      +-------+-------+---------------------+---------------------+
      |Kind=8 |  10   |   TS Value (TSval)  |TS Echo Reply (TSecr)|
      +-------+-------+---------------------+---------------------+
          1       1              4                     4

     The Timestamps option carries two four-byte timestamp fields.
     The Timestamp Value field (TSval) contains the current value of
     the timestamp clock of the TCP sending the option.

     The Timestamp Echo Reply field (TSecr) is only valid if the ACK
     bit is set in the TCP header; if it is valid, it echos a times-
     tamp value that was sent by the remote TCP in the TSval field
     of a Timestamps option.  When TSecr is not valid, its value
     must be zero.  The TSecr value will generally be from the most
     recent Timestamp option that was received; however, there are
     exceptions that are explained below.

这篇关于Ethereal转储中的TSV和TSER字段是什么意思?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！