Guidelines and Limitations for IP SLAs UDP Jitter Operations for VoIP
show commands with the internal keyword are not supported.
This feature uses UDP traffic to generate approximate Voice over IP scores. It does not provide support for the Real-Time Transport Protocol (RTP).
The Calculated Planning Impairment Factor (ICPIF) and MOS values provided by this feature, while consistent within IP SLAs, are estimates only and are intended only for relative comparisons. The values may not match values that are determined using other methods.
Predictions of customer opinion (such as those listed for the E-Model transmission rating factor R and derived Mean Opinion Scores) that are determined by any method are intended only for transmission planning and analysis purposes and should not be interpreted as reflecting actual customer opinions.
One-way delay (latency) measurements do not support the microsecond unit of measurement. Other units of measurement, such as the millisecond, are supported.
Configuring CoPP for IP SLA Packets
When using IP SLA operations on a large scale, a specific CoPP configuration to allow the IP SLA packets to pass through might be needed. Since IP SLA uses user defined UDP ports, there is no way to allow all IP SLA packets to the control plane. However, you can specify each destination/source port that IP SLA can use.
For more information about the verified scalability of the number of IP SLA probes, see the Cisco Nexus 3000 Series NX-OS Verified Scalability Guide.
The following shows an example of a CoPP configuration that allows IP SLA packets to pass through. It assumes destination ports and source ports in the range of 6500-7000.
ip access-list copp-system-sla-allow 10 remark ### ALLOW SLA control packets from 18.104.22.168/24 20 permit udp 22.214.171.124/24 any eq 1967 30 remark ### ALLOW SLA data packets from 126.96.36.199/24 using ports 6500-7000 40 permit udp 188.8.131.52/24 any range 6500 7000 statistics per-entry ip access-list copp-system-sla-deny 10 remark ### this is a catch-all to match any other traffic 20 permit ip any any statistics per-entry class-map type control-plane match-any copp-system-class-management-allow match access-group name copp-system-sla-allow class-map type control-plane match-any copp-system-class-management-deny match access-group name copp-system-sla-deny policy-map type control-plane copp-system-policy class copp-system-class-management-allow set cos 7 police cir 4500 kbps bc 250 ms conform transmit violate drop class copp-system-class-management-deny police cir 4500 kbps bc 250 ms conform drop violate drop control-plane service-policy input copp-system-policy
Matching the Netstack Port Range
IP SLA only accepts ports within the local netstack port range. The source and destination ports used in the probe's configuration must match the supported netstack ports on the SLA sender and the SLA responder.
You can use the show sockets local-port-range command to view the port range on the sender/responder.
The following is an example of viewing the netstack port range:
switch# show sockets local-port-range Kstack local port range (15001 - 22002) Netstack local port range (22003 – 65535)