CANOGA PERKINS 9145E NID Software Version 4.10 - Manual (Page 54)

9145E NID Software User’s Manual Diagnostics
Latency/Jitter Test
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recalculate the CRC of the looped packet when the MAC addresses are swapped, so the
loopback packet can successfully navigate through the network back to the test originator.
At the Diagnostics screen, select Loopback Setup (1) and press Enter. The Loopback Setup
screen (Figure 4-2) opens. Type the number of the function to change, and press Enter. Press
the Space bar to select a setting and then press Enter. Continue to modify the settings as
required. To return to the Diagnostics screen, press Esc.
Figure 4-2 Loopback Setup screen
4.2 Latency/Jitter Test
The Latency/Jitter Test screen is used to initiate tests that measure network latency, inter-frame
jitter, and frame loss from the local 9145E to a remote 9145E or other IP agent. At the
Diagnostics screen, select Latency/Jitter Test (2) and press Enter. The Latency/Jitter Test screen
(Figure 4-3) opens.
The 9145E can be used to generate synthetic test traffic in order to measure frame delay, inter-
frame delay variation and frame loss. A test packet is a standard ICMP Echo Request packet
(RFC 792), with the data area containing fields for proprietary information. If the network element
responding to the Echo Request with an Echo Reply packet is a Canoga Perkins NID, it can
insert some information in the proprietary fields in the data area of the packet. If it is not a
Canoga Perkins NID, the packet will not get discarded, as it is standard ICMP. It will still get
responded to by the non-Canoga network element; however, it will contain less information
important for the Latency/Jitter test results.
Beneath the Maximum Latency and Maximum Jitter test results are the Far End P-Bit Sent/Rcvd,
Local P-Bit Sent/Rcvd, Far End DSCP Sent/Rcvd, and Local DSCP Sent/Rcvd. This data is used
to determine if the programmed Packet Priority or DSCP was changed during the Round Trip
between the local 9145E and the destination 9145E (far end). Only a 9145 or 9145E destination
can provide the Far End PBit/DSCP function.
Canoga Perkins Corp. Ethernet Network Interface Device 29-JAN-2009
9145E-101-1-0 V04.10 11:20:59
------------------------------------LOOPBACK SETUP-----------------------------
Loop Test MAC Address: 00 40 2A 01 EE 11
1) Loopback State Disabled
2) Swap MAC Address
at Loopback Point? Yes
3) Recalculate CRC
at Loopback Point? Yes
Select [1-3]:
------------------------------------Messages-----------------------------------