I have configured IP SLA/SAA on some Catalyst 3550, 3560 & 3750 switches. I am using the following configuration:
rtr responder
rtr 1
type jitter dest-ipaddr x.x.x.x dest-port 32768 source-ipaddr y.y.y.y. source-port 32769 codec g711alaw
tos 184
I have this running both ways (i.e. two switches in the network have the same IP SLA configuration except the IP addresses are reversed). There is no recorded packet loss but the 3560 & 3750 report incrementing 'PacketMIA':
cat-3560-48-s1#sho rtr collection-statistics 1
Entry number: 1
Start Time Index: 14:13:16.264 GMT Tue Mar 6 2007
Number of successful operations: 60
Number of operations over threshold: 0
Number of failed operations due to a Disconnect: 0
Number of failed operations due to a Timeout: 0
Number of failed operations due to a Busy: 0
Number of failed operations due to a No Connection: 0
Number of failed operations due to an Internal Error: 0
Number of failed operations due to a Sequence Error: 0
Number of failed operations due to a Verify Error: 0
Voice Scores:
MinOfICPIF: 1 MaxOfICPIF: 1 MinOfMOS: 4.34 MaxOfMOS: 4.34
RTT Values:
NumOfRTT: 59531 RTTAvg: 1 RTTMin: 1 RTTMax: 5
RTTSum: 102461 RTTSum2: 198607
Packet Loss Values:
PacketLossSD: 0 PacketLossDS: 0
PacketOutOfSequence: 0 PacketMIA: 469 PacketLateArrival: 0
InternalError: 0 Busies: 0
Jitter Values:
MinOfPositivesSD: 1 MaxOfPositivesSD: 3
NumOfPositivesSD: 7086 SumOfPositivesSD: 7299 Sum2PositivesSD: 7741
MinOfNegativesSD: 1 MaxOfNegativesSD: 3
NumOfNegativesSD: 6975 SumOfNegativesSD: 7305 Sum2NegativesSD: 8007
MinOfPositivesDS: 1 MaxOfPositivesDS: 4
NumOfPositivesDS: 12440 SumOfPositivesDS: 14225 Sum2PositivesDS: 18523
MinOfNegativesDS: 1 MaxOfNegativesDS: 4
NumOfNegativesDS: 12505 SumOfNegativesDS: 14211 Sum2NegativesDS: 18207
Interarrival jitterout: 0 Interarrival jitterin: 0
One Way Values:
NumOfOW: 59531
OWMinSD: 0 OWMaxSD: 4 OWSumSD: 54576 OWSum2SD: 58018
OWMinDS: 0 OWMaxDS: 4 OWSumDS: 47885 OWSum2DS: 57663
The same configuration with a Catalyst 3550 shows no PacketMIA's (3550 one end, 3560/3750 at the other end). This is all on a test network so there is no real traffic, QoS is enabled but I have tried the same rtr configuration without any ToS being set, so sent and handled in the middle of the test network as best-effort. I have checked with a colleage and he has seen exactly the same behaviour so I am assuming this is behaviour specific to the 3560/3750 platform and perhaps a bug?
I have looked through the Bug navigator and all I could find was a bug in 12.3T (CSCeg13677). I am running the very latest code for all the switches involved- 3560 12.2(35)SE1, 3750 12.2(35)SE2, 3550 12.2(35)SE. I have also downgraded a 3560 to 12.2(35)SE and 12.2(25)SEE2 and the behaviour remains the same.
Has anyone else experienced this behaviour or managed to find a workaround?
Thanks
Andy
