Timestamp Definitions and Values in the Request

The following table provides an explanation for each of the values in the [timestamp] section of the request:

Table 1. Timestamp values and definitions
Value Description
RequestTimeEx Start of the request. The timestamp when the DNCA saw the first packet of the request.
RequestEndTimeEx End of the request. The timestamp when the DNCA saw the last packet of the request.
ResponseStartTimeEx Start of the response. The timestamp when the DNCA saw the first packet of the response. If no response packets were seen, then the RequestEndTimeEx value will be used.
ResponseTimeEx End of the response. The timestamp when the DNCA saw the last packet of the response. If no response packets were seen, then the RequestEndTimeEx value will be used.
ResponseAckTimeEx Timestamp when the DNCA saw that client/browser acknowledged the last TCP packet of the response. If no response packets were seen, then the RequestEndTimeEx value will be used.
TLapiArrivalTimeEx This timestamp indicates when the hit arrives within the DNCA's pipelined process. The completed reassembled hit time may be much later if an incomplete hit was reassembled or was delayed due to a very late last data packet. In an otherwise normal case, this timestamp should be roughly the same as the ResponseTimeEx. A large difference could indicate a network issue.
ReqTTLB Time in microseconds from the first packet of the request to the last packet of the request (RequestEndTimeEx minus RequestTimeEx). This value does not include network time.
RspTTFB Time (in microseconds) from the start of the request to the first of the response page (ResponseTimeStartEx minus RequestTimeEx). This value is usually an accurate approximation of the time that the Web server required to generate the response page. In particular, if the entire page is buffered (the default for ASP .NET and many J2EE environments), then this measurement is an exact predictor of how long the server-side infrastructure took to respond.

This value may not be accurate if the Web server served the data in chunks.

RspTTLB Time in microseconds from the first packet of the response to the last packet of the response (ResponseTimeEx minus ResponseStartTimeEx). This value does not include network time.
RspTDCA Client/browser acknowledgement time of the last data packet (ResponseACKTimeEx minus ResponseTimeEx). This value is an indication of network round trip.

To compute one-way time, divide this value by 2.

ConnSpeed Connection speed, specified in bits per second (bps). This value is calculated by dividing the average size of the response by the average time it took to deliver.

When determining connection speed, any detected client user interface events are ignored.

ConnType Based on the ConnSpeed setting, this value is set to Dialup, ISDN, DSL, or T1.
WS_Generation Time in microseconds for the web server to generate the response. This value is computed as: ResponseStartTimeEx - RequestEndTimeEx
WS_Grade The grade assigned to the web server page generation time (WS_Generation). Possible values are the following: ExcellentWS, Very GoodWS, GoodWS, FairWS, PoorWS, or IncompleteWS.

This value is indexed by default.

WS_GradeEx A number representing the TimeGrades time range grouping between 0 and 4 for web server page generation time. See Pipeline Settings.
NT_Total Time in microseconds for the network travel time.
NT_Grade The grade assigned to the network travel time (NT_Total). Possible values are the following: ExcellentNT, Very GoodNT, GoodNT, FairNT, PoorNT, or IncompleteNT.

This value is indexed by default.

NT_GradeEx A number representing the TimeGrades time range grouping between 0 and 4 for network travel time.
RT_Total The total round trip travel time in microseconds.
RT_Grade The overall grade for network performance. Possible values are the following: ExcellentRT, Very GoodRT, GoodRT, FairRT, PoorRT, or IncompleteRT.

This value is indexed by default.

RT_GradeEx A number representing the TimeGrades time range grouping between 0 and 4 for round trip travel time. See Pipeline Settings.