User manual

17-4
Cisco ONS 15310-CL and Cisco ONS 15310-MA Ethernet Card Software Feature and Configuration Guide R8.5
78-18133-01
Chapter 17 CE-100T-8 Ethernet Operation
CE-100T-8 Ethernet Features
Enhanced State Model for Ethernet and SONET Ports
The CE-100T-8 supports the Enhanced State Model (ESM) for the Ethernet ports, as well as for the
SONET circuit. For more information about the ESM, refer to the “Administrative and Service States”
appendix in the Cisco ONS 15454 Reference Manual.
The Ethernet ports can be set to the ESM service states including the In-Service, Automatic In-Service
(IS,AINS) administrative state. IS,AINS initially puts the port in the Out-of-Service and Autonomous,
Automatic In-Service (OOS-AU,AINS) state. In this service state, alarm reporting is suppressed, but
traffic is carried and loopbacks are allowed. After the soak period passes, the port changes to In-Service
and Normal (IS-NR). Raised fault conditions, whether their alarms are reported or not, can be retrieved
on the CTC Conditions tab or by using the TL1 RTRV-COND command.
Two Ethernet port alarms/conditions, CARLOSS and TPTFAIL, can prevent the port from going into
service. This occurs even though alarms are suppressed when a CE-100T-8 circuit is provisioned with
the Ethernet ports set to the IS,AINS state, because the CE-100T-8 link integrity function is active and
ensures that the links at both ends are not enabled until all SONET and Ethernet errors along the path
are cleared. As long as the link integrity function keeps the end-to-end path down, both ports will have
at least one of the two conditions needed to suppress the AINS-to-IS transition. Therefore, the ports will
remain in the AINS state with alarms suppressed.
ESM also applies to the SONET circuits of the CE-100T-8 card. If the SONET circuit is set up in
IS,AINS state and the Ethernet error occurs before the circuit transitions to IS, then link integrity will
also prevent the circuit transition to the IS state until the Ethernet port errors are cleared at both ends.
The service state will be OOS-AU,AINS as long as the administrative state is IS,AINS. When there are
no Ethernet or SONET errors, link integrity enables the Ethernet port at each end. Simultaneously, the
AINS countdown begins as normal. If no additional conditions occur during the time period, each port
transitions to the IS-NR state. During the AINS countdown, the soak time remaining is available in CTC
and TL1. The AINS soaking logic restarts from the beginning if a condition appears again during the
soak period.
A SONET circuit provisioned in the IS,AINS state remains in the initial Out-of-Service (OOS) state until
the Ethernet ports on each end of the circuit transition to the IS-NR state. The SONET circuit transports
Ethernet traffic and counts statistics when link integrity turns on the Ethernet port, regardless of whether
this AINS-to-IS transition is complete.
IEEE 802.1Q CoS and IP ToS Queuing
The CE-100T-8 references IEEE 802.1Q class of service (CoS) thresholds and IP type of service (ToS)
(IP Differentiated Services Code Point [DSCP]) thresholds for priority queueing. CoS and ToS thresholds
for the CE-100T-8 are provisioned on a per port level. This allows the user to provide priority treatment
based on open standard quality of service (QoS) schemes already existing in the data network attached
to the CE-100T-8. The QoS treatment is applied to both Ethernet and POS ports.
Any packet or frame with a priority greater than the set threshold is treated as priority traffic. This
priority traffic is sent to the priority queue instead of the normal queue. When buffering occurs, packets
on the priority queue preempt packets on the normal queue. This results in lower latency for the priority
traffic, which is often latency-sensitive traffic, such as VoIP.
Because these priorities are placed on separate queues, the priority queuing feature should not be used
to separate rate-based CIR/EIR marked traffic (sometimes done at a Metro Ethernet service provider
edge). This could result in out-of-order packet delivery for packets of the same application, which would
cause performance issues with some applications.