Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 1071)

Brocade 6910 Ethernet Access Switch Configuration Guide 1015
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Connectivity Fault Management
• Previous LMR frame's TxFCf, RxFCf and TxFCb values and local counter RxFC1 value at the
time the previous LMR frame was received. These values are represented as TxFCf[t
p
],
RxFCf[t
p
], TxFCb[t
p
] and RxFCl[t
p
], where t
p
is the reception time of the previous reply
frame.
Frame loss far-end = |TxFCf[t
c
] – TxFCf[t
p
]| – |RxFCf[t
c
] – RxFCf[t
p
]|
Frame loss near-end = |TxFCb[t
c
] – TxFCb[t
p
]| – |RxFCl[t
c
] – RxFCl[t
p
]|
Dual-Ended Loss Measure
• Dual-ended loss measurement is carried out by sending periodic CCM PDUs with loss
measurement (LM) information to facilitate frame loss measurements at the peer MEP. Each
MEP makes the near-end loss measurements (frame loss associated with ingress data frames)
and far-end loss measurements (frame loss associated with egress data frames).
The CCM PDU carrying dual-ended loss measure information is transmitted at an interval
configured by the “Interval Level” parameter set on the Configure MA (Configure Details) page.
To perform loss measurement, a MEP periodically transmits CCM frames with the following
elements:
• TxFC1 – Counter for in-profile data frames transmitted towards the peer MEP.
• TxFCf – Value of the local counter TxFC1 at the time of transmission of the CCM frame.
• RxFC1 – Counter for in-profile data frames received from the peer MEP.
• RxFCb – Value of the local counter RxFC1 at the time of reception of the last CCM frame
from the peer MEP.
• TxFCb – Value of TxFCf in the last received CCM frame from the peer MEP.
Upon receiving a CCM frame, a MEP uses the following values to make near-end and far-end
loss measurements:
• Received CCM frame's TxFCf, RxFCb and TxFCb values and local counter RxFC1 value at
the time this CCM frame was received. These values are represented as TxFCf[t
c
],
RxFCb[t
c
], TxFCb[t
c
] and RxFCl[t
c
], where t
c
is the reception time of the current frame.
• Previous CCM frame's TxFCf, RxFCb and TxFCb values and local counter RxFC1 value at
the time the previous CCM frame was received. These values are represented as TxFCf[t
p
],
RxFCb[t
p
], TxFCb[t
p
] and RxFCl[t
p
], where t
p
is the reception time of the previous frame.
Frame loss far-end = |TxFCb[t
c
] – TxFCb[t
p
]| – |RxFCb[t
c
] – RxFCb[t
p
]|
Frame loss near-end = |TxFCf[t
c
] – TxFCf[t
p
]| – |RxFCl[t
c
] – RxFCl[t
p
]|
Parameters
These parameters are displayed:
Add Single-Ended LM Group
• Group Index – Attribute group index. (Range: 1-200)
• Cycle – The periodic cycle at which loss-measure messages are transmitted.
(Range: 1-24 hours; Default: 4 hours)
• Duration – The duration of each transmission. (Range: 1-60 minutes; Default: 10 minutes)
• Interval – The interval between each transmission. (Range: 1-5 minutes; Default: 1 minute)
This parameter must be less than or equal to the "Duration" parameter.
• Timeout – The timeout to wait for a response. (Range: 1-5 seconds; Default: 1 seconds)