The link of dark-fibre down for 5 months. Few weeks ago, got their error message-- BIOS (send to RAM)
As clients received the replaced SW 3850 from cisco, we went to client site to fix the issue.
Dark Fibre is a fibre-optic point to point connectivity solution that provides customer full control of their network and also allow clients to enjoy security and reliability of their network.
Notes from work:
Dark-Fibre usually designed for critical sites, there are below several tasks need to reach
1. Error diable auto-discovery:
udld autorecovery:
UDLD is an mechanism to avoid fiber link loops. Fibre Tx is physical separated from Rx, such as SC, ST, LC, FC and so on. There are possibility of loop by mis-plug.
UDLD in a mechanism to detect TX, and RX to detect if any loops in network.
There are two type of udld mechanism as loops caused:
1. UDLD aggressive, that will "error-diable" interface
2. UDLD enable, that will send "error message" to admin.
In Global config, existing "usls aggressive", an admin is better to config "errdisable recovery cause udld" in Error diable auto-discovery parts to avoid any future unexpected interface down.
2. How to verify Fiber interface work operationally:
"show interface transceiver detail" to verify the interface the receive and transmit signal. The deep explanation below:
XXXX#sh int transceiver detail
mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable.
++ : high alarm, + : high warning, - : low warning, -- : low alarm.
A2D readouts (if they differ), are reported in parentheses.
The threshold values are calibrated.
High Alarm High Warn Low Warn Low Alarm
Temperature Threshold Threshold Threshold Threshold
Port (Celsius) (Celsius) (Celsius) (Celsius) (Celsius)
--------- ------------------ ---------- --------- --------- ---------
Te1/1/1 32.6 75.0 70.0 0.0 -5.0
High Alarm High Warn Low Warn Low Alarm
Voltage Threshold Threshold Threshold Threshold
Port (Volts) (Volts) (Volts) (Volts) (Volts)
--------- --------------- ---------- --------- --------- ---------
Te1/1/1 3.27 3.63 3.46 3.13 2.97
Optical High Alarm High Warn Low Warn Low Alarm
Transmit Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
--------- ----------------- ---------- --------- --------- ---------
Te1/1/1 0.1 7.0 4.0 -4.7 -8.6
Optical High Alarm High Warn Low Warn Low Alarm
Receive Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
------- ----------------- ---------- --------- --------- ---------
Te1/1/1 -4.2 2.0 -1.0 -15.8 -19.7
According to this link, 10G ER must fulfil this requirement:
TX: 4.0 dBm ~ -4.0 dBm ( we got 0.1 dBm )
RX: -1 dBm ~ -15.8 dBm ( we got -4.2 dBm )
http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/data_sheet_c78-455693.pdf
Notes for Understanding Dark-Fiber benefits
1. Freedom : the clients will enjoy full control of network by have a freedom to select the transmission technology of clients' choice to deploy over a Point-to-point connection. This Priorate WAN connection runs Gigabit /TenGigabit Ethernet, ATM, or any adopted protocol.
2. Reliability: Reliability is required all the time in WANs, and Dark-Fibre allows the clients to specify the point-to-point route that they need to connect their WANs, resulting in a direct circuit to get from point A to Point B. Due to only clients' traffic operating over Dark Fibre, it will reach a Carrier-Grade SLA that easily makes the service very reliable.
3. Security: Point-to-point Dark Fibre networks provide clients a very secure way to connect business mission between critical sites.
4. Performance: Almost unlimited bandwidth potential of optical fibre, and it is with nearly no intervening electronics of any kind the service.