How Does The SBC Calculate The Latency In The Agents?

Asset ID:	1-71-2260817.1
Update Date:	2017-05-31
Keywords:

Solution Type Technical Instruction Sure

Solution 2260817.1 : How Does The SBC Calculate The Latency In The Agents?

Applies to:

Acme Packet 4500 - Version S-Cz7.2.0 and later
Information in this document applies to any platform.

Goal

How does the SBC calculate the latency in the agents?

Solution

Latency statistics:
• Avg: average latency for packets traveling to and from each session agent listed
• Max: maximum latency for packets traveling to and from each session agent listed
• Max Burst: total number of session invitations sent to or received from the session agent within the amount of
time configured for the burst rate window of the session agent

Avg Latency
Average observed one-way signaling latency during the active window period.
This is the average amount of time the signaling travels in one direction.
Max Latency
Maximum observed one-way signaling latency during the sliding window period.
This is the maximum amount of time the signaling travels in one direction.

The latency for the output of is measured in seconds.

> show sipd agents
00:01:41-50 (recent)
----- Inbound ----- ---- Outbound ----- -- Latency -- Max
Session Agent Active Rate ConEx Active Rate ConEx Avg Max Burst
XYZ.com
I 9 0.0 0 68 0.1 0 1.271 27.514 16
ABC.com
I 56 0.0 0 66 0.1 0 1.122 23.518 15

Because in this case for SA: XYZ.com with Max Latency of 27.515 seconds and Avg: 1.271 I suppose it had traffic affection because there are high values, Hadn´t it?
---------------------
It cannot be said that whether Max Latency of 27.515 seconds will affect traffic or not. This is because the max-latency is calculated for a single packet.
Hence, it could be just one call in the traffic that will get affected. The more details can be seen from the call trace.

Here is an example
The first invite is sent through waiting to respond 31 seconds, and then sent 10 more with immediate response, max is always that 1, and the average is for all 11
# show sipd invite
INVITE (03:40:17-190)
  --------- Server -------- --------- Client --------
Message/Event Recent Total PerMax Recent Total PerMax
  ------ --------- ------ ------ --------- ------
INVITE Requests 1 3 1 1 4 1
Retransmissions 0 0 0 6 18 6
100 Trying 1 3 1 0 0 0
180 Ringing 1 3 1 1 3 1
200 OK 0 2 1 0 2 1
408 Request Timeout 0 1 1 0 0 0
Response Retrans 0 0 0 0 0 0
Transaction Timeouts - - - 0 2 1
Locally Throttled - - - 0 0 0

Avg Latency=31.509 for 1
Max Latency=31.509

# show sipd invite
INVITE (03:40:29-102)
  --------- Server -------- --------- Client --------
Message/Event Recent Total PerMax Recent Total PerMax
  ------ --------- ------ ------ --------- ------
INVITE Requests 11 13 11 11 14 11
Retransmissions 0 0 0 7 19 7
100 Trying 11 13 11 0 0 0
180 Ringing 11 13 11 11 13 11
200 OK 11 13 7 11 13 7
408 Request Timeout 0 1 1 0 0 0
Response Retrans 0 0 0 0 0 0
Transaction Timeouts - - - 0 2 1
Locally Throttled - - - 0 0 0

Avg Latency=2.913 for 11
Max Latency=31.509

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