ERPS Management

Ethernet ring protection applies to ring networks. It uses the R-APS protocol to achieve fast protection switching on an Ethernet ring network. You are advised to create ERPS V2 to protect Ethernet services on a multiple-ring network consisting of FE or GE ports or integrated IP microwave ports. In this user interface, you can create an Ethernet ring protection group and query information about the Ethernet ring protection.

Navigation Path

Click the NE in the NE Explorer and select the required board. Choose Configuration > Ethernet Protection > ERPS Management from the Function Tree.

In the NE Explorer, choose Configuration > Ethernet Protection > ERPS Management from the Function Tree.

Guideline

The rules for configuring the Ethernet ring protection are as follows:

Ethernet ring protection applies only to ring networks and supports the network consisting of only one ring currently.
At least one EM6T board must be configured at each station.
The revertive mode must be set to revertive.

The automatic Ethernet ring protection switching can be triggered on any of the following conditions:

Board fault: A key board is faulty (for example, the line board is powered off or offline).
In the case of system-side ports,
- If link capacity adjustment scheme (LCAS) is not enabled, the trigger conditions are as follows: TU_LOP, AU_LOP, MS_AIS, AU_AIS, TU_AIS, B3_EXC, BIP_EXC, HP_UNEQ, LP_UNEQ, VCAT_SQM_VC4, VCAT_SQM_VC3, VCAT_LOM_VC4, VCAT_LOM_VC3, and VCAT_LOA.
- If LCAS is enabled, the trigger condition is the unavailability of all members in the virtual concatenation group (VCG).
In the case of Ethernet ports, the trigger conditions are R_LOS, LINK_ERR, and LSR_NO_FITED.

NOTE:

If a VCG port is not bound with any VC, the VCG port is normal and will not trigger ERPS switching.

The rules for creating ERPS protection (V2) are as follows:

A maximum of eight ERPS instances are allowed on an NE.
All ring nodes use same parameter settings for the ERPS protocol.
If the quantity of nods is overlarge on the entire ERPS V2 multiple-ring network, the speed of ERPS switching will be affected.

NOTICE:

Deleting an instance may damage the ERPS.

Parameter Description

**Table 1** Parameters in Ethernet Ring Protection
Parameter	Value	Description
ERPS ID	1-8	Displays and sets the ERPS ID.
East Port	For example: 2–EM6F-2	Displays and sets the east port of a ring node.
West Port	For example: 2–EM6F-2	Displays and sets the west port of a ring node.
ERP Ring Node Flag	Next Neighbor Port, Neighbor Port, RPL Port, None	Displays and sets the ring node flag in the ring. NOTE: ERP Ring Node Flag is a parameter for RTN 980s and is similar to the RPL Owner Ring Node Flag parameter for MSTP OSN 500 series NEs.
Flag Port	For example: 2–EM6F-2	Displays and sets the Flag port. NOTE: This parameter is similar to the RPL Port parameter for MSTP OSN 500 series NEs. This parameter is invalid only when ERP Ring Node Flag is set to None.
Control VLAN	1-4094	Displays and sets the control VLAN that is used to carry R-APS messages. Control VLAN cannot be the same as service VLAN.
Destination Node	For example: 01-19-A7-00-00-01	Displays the MAC address of the destination node. The default destination MAC address of R-APS messages is 01-19-A7-00-00-01.
Loop Detect	Enabled, Disabled	Specifies whether to detect loops on an ERPS ring. This parameter can be set only when RPLOwner Ring Node Flag is set to Yes. NOTE: If all devices on the ERPS ring are provided by Huawei, set this parameter to Enabled to increase the loopback rectification efficiency and achieve fast switching. If any devices on the ERPS ring are not provided by Huawei, set this parameter to Disabled to ensure compatibility.
ETH Type Domain	Transfer Mode, Standard Mode Default: Transfer Mode	Indicates the Ethernet type of an ERPS ring. If the ERPS ring contains only transport NEs, set this parameter to Transfer Mode. If the ERPS ring contains non-transport NEs, set this parameter to Standard Mode.
Current Node	For example: 01-19-A7-00-00-01	Displays the MAC address of the current node.
Virtual Channel Status	Disabled, Enabled	Displays and sets whether to enable virtual channels. NOTE: Modifying virtual channel status will cause abnormal protocol status.
Virtual Channel VLANs	1-4094	Displays and sets VLANs for virtual channels. NOTE: For Sub-ring, Virtual Channel VLAN is Control VLAN.
Major ERPS Ring ID	1-8	Displays and sets the major ERPS ring ID to associate with the major ring.
Virtual Channel VLAN on Major Ring	1-4094	Displays and sets
Hold-Off Time (ms)	0-10000, in step of 100 Default: 0	Displays and sets the hold-off time for ERPS. When a new fault or more faults occur, the hold-off timer starts if the preset hold-off timer value is non-zero. When the hold-off timer is running, the fault is not reported to ERPS. When the hold-off timer expires, the link state is checked regardless of whether the defect persists. If there is a fault, the fault is reported to ERPS for protection switching. The reported fault need not be the same as the fault that starts the hold-off timer. The hold-off timer is used to coordinate protection switching time between ERPS and other existing protection schemes. Its purpose is to allow the protection switching at another layer or level (for example, the LAG protection at ports) to have a chance to fix the problem before ERPS switching.
WTR Time (mm:ss)	01:00, 02:00, 03:00, 04:00, 05:00, 06:00, 07:00, 08:00, 09:00, 10:00, 11:00, 12:00 Default: 05:00	Displays and sets the WTR time for ERPS. Sets the WTR time. WTR time refers to the period between the time when the working channel is recovered and the time when the services are switched back to the working channel. The period from the time when the original working channel is recovered to normal to the time when the NE releases the switching is called the wait-to-restore (WTR) time. When the original working channel is recovered to normal, the WTR timer on the RPL owner starts. While the timer is running, a WTR running signal is continuously generated. After the timer expires and no switching request of higher priority is received, the WTR timer stops generating the WTR running signal but starts to continuously generate the WTR expire signal. The WTR timer is used to prevent the frequent switching actions due to instability of the working channel.
Guard Time (ms)	For example: 500	Displays and sets the guard time for ERPS. During the guard time, the received R-APS message is discarded. When the guard time expires, the received R-APS message is forwarded directly. R-APS messages are periodically transmitted over the ring and the status of the ring nodes may change at any moment. This can result in an outdated and useless R-APS message being received by ring nodes. The reception or forwarding of the outdated messages may result in erroneous protection switching decisions. The guard timer is used to prevent ring nodes from receiving outdated R-APS messages.
Packet Transmit Interval (s)	1-10	Displays the transmit interval for R-APS messages.
Entity Level	0-7	Displays and sets the entity level.
Last Switching Request	Raps (NR), Raps (NR, RB), WTR, WTR Expires, Raps (SF), Local SF, Local Clear SF, Initial Request	Displays the last switching request.
RB Status	noRB, RB	Displays the RB status of the message received at the current node.
DNF Status	noDNF, DNF	Displays the DNF status of the message received at the current node.
State Machine Status	Idle, Protection, ForceSwitch, ManualSwitch	Displays the status of the state machine at the current node.
MAC Address Carried in Packets	For example, 00-21-97-02-DA-16	Displays the MAC address in the message received at the current node, that is, the MAC address of the source node of the switching request.
East Port Status	Block, Unblock	Displays the status of the east port.
West Port Status	Block, Unblock	Displays the status of the west port.
Revertive Mode	Revertive, Non-Revertive, -	Sets the revertive mode. Revertive: Indicates that services are switched back to the working channel automatically after the fault in the working channel is rectified. Non-Revertive: Indicates that services are not switched back to the working channel automatically after the fault in the working channel is rectified. NOTE: When ERP Ring Node Flag is RPL Port, Revertive Mode can be compiled.
Compatible_Version	ver1, ver2	Sets the ERPS protocol version. You can change the ERPS protocol version for created ERPS services as required. ERPS protocol versions on nodes of the same EPRS ring must be the same. EPRS protocols of different versions may be incompatible. NOTE: Only the EPRS protocol of ver2 supports the Revertive Mode and the Switching operations. In the following case, Compatible_Version cannot be edited: only one port between East Port and West Port is set in the instance. Virtual Channel Status is Disabled in the instance. Virtual Channel VLAN has been set in the instance. When Compatible_Version is ver1: Revertive Mode would be set as Revertive automatically. Virtual Channel Status and Virtual Channel VLAN cannot be set.