What's the Reversion Failures of a Revertive Tunnel Coexisting with the SNCTP

Product Line: Transport network    Product Model: OptiX OSN 1500/OSN 2500/OSN 3500/OSN 7500

[Problem Description]

Trigger condition:

1. A revertive tunnel and static SNCTP receive/transmit lower order services in back-to-back mode.

2. The revertive tunnel is rerouted, or optimized after a rerouting.

Symptom:

The tunnel cannot be reverted to the original trail, or tunnel optimization fails. CP_LSP_SIG_EXCEPT and CP_SER_NOT_OR alarms are reported, respectively indicating that the ASON signaling is abnormal and the service is not on the original trail.

The two alarms are not supported in earlier versions.

Identification method:

This issue can be identified when the following three conditions are met:

1. The revertive tunnel and static SNCTP receive/transmit lower order services in back-to-back mode.

3. The tunnel is rerouted, and then reverted to the original trail or optimized.

4. The function of 1+1 linear MSP lower order broadcast optimization is disabled.

[Root Cause]

After the tunnel is rerouted, only part of the cross-connection information at the algorithm layer of the NE software is updated. If the tunnel is reverted to the original trail or optimized, the newly generated services conflict with the cross-connection information that is not updated. As a result, the tunnel reversion or optimization fails.

[Impact and Risk]

The revertive tunnel cannot be reverted to the original trail, or the tunnel optimization fails.

[Measures and Solutions]

Recovery measures:

Enable the 1+1 linear MSP lower order broadcast optimization function, and manually trigger a full calculation. After the tunnel service is reverted to the original trail and the CP_LSP_SIG_EXCEPT alarm is cleared, disable the 1+1 linear MSP lower order broadcast optimization function.

Preventive measures:

Do not configure the static SNCTP and tunnel in back-to-back mode.

Solution:

Upgrade an NE to one of the following versions:

l If the NE version is one of V100R006, V100R007, or V100R008 versions earlier than V100R008C02SPC500, upgrade the NE to V100R008C02SPC500 or a later V100R008 version.

l If the NE version is one of V100R009 or V100R010 versions earlier than V100R010C03SPC200, upgrade the NE to V100R010C03SPC200 or a later version.

For V100R010C03SPC200 or a later version, the SNCTP protection cannot be configured for VC-4 services. Rectification needs to be made to an NE whose VC-4 services are configured with SNCTP protection before an upgrade.

Material handling after replacement:

N/A

[Inspection Tool Applicable or Not]

N/A

[Rectification Scope and Time Requirements]

N/A

[Rectification Instructions]

N/A

[Attachment]

N/A

More blog:

NE Configuration Loss Due to Disabling of the Automatic and Periodic Database Backup Functions on MSTP Products

How to Troubleshoot Synchronous Ethernet Clocks For Huawei SDH

Be aware of SSN3PSXCSA replace Cross-connect Board on OptiX OSN 3500

Typical NETworking in packet mode of Huawei OSN 1500

In packet mode, Huawei OptiX OSN 1500 mainly supports two different typical networking scenarios, depending on whether routers are used.

Typical Networking Without Routers

Huawei OptiX OSN equipment can construct a network where TDM services and packet services are transmitted between base stations and the RNC without assistance from routers.
NE1 and NE2 are generally OptiX OSN 1500 or OptiX OSN 500 or OptiX OSN 550 NEs; NE3, NE4, NE5, and NE6 are generally Huawei OptiX OSN 3500 or OptiX OSN 7500 or OptiX OSN 7500 II NEs; NE7 and NE8 are generally OptiX OSN 7500 or OptiX OSN 7500 II NEs. 

FE services from NodeBs at the access layer are aggregated to the GE packet ring through NE1 and NE2, then to the 10GE packet rings through NE3 and NE6, and finally to the RNC.

Hybrid Networking with Routers

Hybrid MSTP equipment on a Layer 2 network can be connected to an RNC through routers, which provide powerful Layer 3 switching capabilities and enhance network scalability.

Service Bearing This solution supports TDM services and Ethernet/IP services.

• TDM services are carried by single-homed SDH equipment.

·   Ethernet and IP services are carried by an L2VPN on the Hybrid MSTP network, and are forwarded based on IP addresses or carried by an L3VPN on the CX network.

The Hybrid MSTP network transmits E-Line or E-LAN services to its interconnected CX equipment. The CX equipment terminates Layer 2 VLANs and transmits services to Layer 3.

Network Topologies The Hybrid MSTP equipment can be interconnected with routers to form a ring or chain network. There are various types of equipment applicable to each transmission layer.

• Access layer: OptiX OSN 1500, OptiX OSN 500, or OptiX OSN 550
• Convergence layer: OptiX OSN 3500, OptiX OSN 7500, or OptiX OSN 7500 II
• Layer 3: OptiX OSN 7500, OptiX OSN 7500 II, or CX 600

Common network topologies are as follows:

• Triangle-shaped network

MPLS tunnel/PW APS is configured between Hybrid MSTP access equipment and Hybrid MSTP convergence equipment. LAGs are configured on Hybrid MSTP convergence equipment and E-Trunks are configured on CX equipment to protect services on the links in between.

• Rectangle-shaped network

MPLS tunnel/PW APS groups that are co-sourced but not co-sinked are configured on the Hybrid MSTP equipment that is connected to base stations. Working and protection tunnels/PWs are separately terminated on two pieces of Hybrid MSTP equipment that is connected to CX equipment. E-LANs are configured on the Hybrid MSTP equipment connected to CX equipment and VRRP groups are configured on CX equipment to provide link-level and equipment-level protection. Convergence equipment is dual-homed to shed the risks that convergence and Layer 3 equipment faults bring about.

More blog:

NE Configuration Loss Due to Disabling of the Automatic and Periodic Database Backup Functions on MSTP Products

How to Troubleshoot Synchronous Ethernet Clocks For Huawei SDH

10G services on OSN 8800 layer interrupted

Huawei OptiX OSN 3500 SDH PDH

The OptiX OSN 3500 Intelligent Optical Transmission System is a new-generation intelligent optical transmission system developed by Huawei Technologies. The system provides high-efficiency transmission of various services, such as SDH, PDH, Ethernet, ATM, DDN, and SAN, at the core layer and edge layer. By using packet switching technology the system can provide carrier-level QoS on the packet transport network.

Positioning

The OptiX OSN 3500 intelligent optical transmission system (the OptiX OSN 3500 for short) developed by Huawei is the next-generation intelligent optical transmission equipment. The OptiX OSN 3500 is of a “universal switch” architecture. That is, the OptiX OSN 3500 can be used in packet mode or in TDM mode. When used with the other equipment of Huawei, the OptiX OSN 3500 supports various networking applications, such as the pure packet mode application, hybrid networking application (overlay networking of the packet mode and TDM mode), and pure TDM mode application. By using a proper networking solution, the data service and conventional SDH service can be processed in the optimal manner.

Technology

The OptiX OSN 3500 transmits voice and data services on the same platform with high efficiency. It integrates the following technologies:

• In packet mode, the OptiX OSN 3500 supports the following technologies: In TDM mode, the OptiX OSN 3500 supports the following technologies:
  • Multiprotocol Label Switching (MPLS)
  • Multiprotocol Label Switching Transport Profile (MPLS-TP)
  • Pseudo Wire Edge to Edge Emulation (ETH PWE3)
  • TDM PWE3
  • ATM PWE3
• In TDM mode, the OptiX OSN 3500 supports the following technologies:

• Synchronous digital hierarchy (SDH)
• Plesiochronous digital hierarchy (PDH)
• Ethernet
• Asynchronous transfer mode (ATM)
• Storage area network (SAN)/Video
• Wavelength division multiplexing (WDM)
• Digital data network (DDN)

Network Application

As shown in Figure 2, the OptiX OSN 3500 is mainly used at the convergence layer and backbone layer of the metropolitan area network (MAN). The network application scenarios are described as follows:

• In TDM networking, can be networked with the other OptiX transmission equipment (the OptiX OSN 9560, OptiX OSN 9500, OptiX OSN 7500 II, OptiX OSN 7500, OptiX OSN 3500 II, OptiX OSN 2500, OptiX OSN 1500, OptiX OSN 500, and OptiX OSN 550) to optimize the carrier’s investment.
• With the packet switching technology, can constitute a packet data transmission network with the other OptiX transmission equipment (the OptiX OSN 7500 II, OptiX OSN 7500, OptiX OSN 1500, OptiX OSN 500, OptiX OSN 550, OptiX PTN 910, OptiX PTN 950, OptiX PTN 1900, OptiX PTN 3900, and OptiX RTN 900) to meet the requirement for bearing IP services.
• Can be flexibly networked with WDM equipment and Metro equipment.
• Can transparently transmit services over third-party Layer 2 networks, allowing end-to-end configuration and management.

Features

• Universal Switch Architecture for Multiservice Grooming OptiX OSN equipment uses a universal switch architecture for unified grooming of packet services and TDM services. OptiX OSN equipment can work in packet mode, TDM mode, or dual-domain (packet+TDM) mode.
• Hierarchical OAM Facilitating Fault Detection The Hybrid MSTP equipment supports hierarchical OAM to rapidly detect and locate various faults, thereby improving network reliability. In addition, the Hybrid MSTP equipment supports distributed OAM and centralized OAM.
• TP-Assist Solution Facilitating the O&M of Packet Services Like the SDH equipment, Huawei Hybrid MSTP equipment supports a hierarchical operating & maintenance (O&M) system by using the TP-Assist solution, so packet services can be configured, commissioned, or maintained in an end-to-end manner.
• Built-In WDM, Flexible Networking The OptiX OSN equipment uses the built-in WDM technology to transmit several wavelengths over one optical fiber. In this manner, the OptiX OSN equipment can be interconnected with the WDM equipment.

Board Software

The board software runs on each board and it manages, monitors and controls the operation of the board. It receives the command issued from the NE software and reports the board status to the NE software through performance events and alarm. The specific functions include:

• Alarm management
• Performance management
• Configuration management
• Communication management

It directly controls the functional circuits in corresponding boards and implements ITU-T compliant specific functions of the NE.

Table 1 Maximum switching capacity of the OptiX OSN 3500

Board                                   Maximum Switching Capacity          Access Capacity of a Single Subrack

N1PSXCS                                                80 Gbit/s                                          60 Gbit/s

N2PSXCSA, N3PSXCSA                      160 Gbit/s                                       100 Gbit/s

Table 2  Service types that the OptiX OSN 3500 supports

Service Type	Description
SDH services	· Standard SDH services: STM-1/STM-4/STM-16/STM-64 · Standard SDH concatenated services: VC-4-4c/VC-4-8c/VC-4-16c/VC-4-64c/AU-3· Standard SDH virtual concatenation services: VC-4-Xv (X≤8), VC-3-Xv (X≤24), VC-12-Xv (X≤63) · SDH services with FEC: 10.709 Gbit/s, 2.666 Gbit/s
PDH services	· E1 (optical) service · E1 (electrical)/T1 service · E3/T3 service · E4 service
Ethernet services	· Ethernet private line (EPL) service · Ethernet virtual private line (EVPL) service · Ethernet private LAN (EPLAN) service · Ethernet virtual private LAN (EVPLAN) service
RPR services	· EVPL service · EVPLAN service
ATM services	· Constant bit rate (CBR) service · Real-time variable bite rate (rt-VBR) service · Non real-time variable bite rate (nrt-VBR) service · Unspecified bit rate (UBR) service
DDN services	· Nx64 kbit/s (N = 1-31) service · Framed E1 service
SAN services	· Fiber channel (FC) service · Fiber connection (FICON) service · Enterprise systems connection (ESCON) service
Video services	· Digital video broadcast-asynchronous serial interface (DVB-ASI) service · High definition-serial digital interface (HD-SDI) electrical service · Standard definition-serial digital interface (SD-SDI) electrical service

Table 3 Power supply parameters

Item                                    Specification

Power supply mode        DC power supply

Nominal voltage              -48 V or -60 V

Voltage range                   -38.4 V to -57.6 V or -48 V to -72 V

Maximum current             20 A/32 Aa/60 Ab

a: This value indicates the maximum current of the equipment when the enhanced subrack (1100 W) is used.

b: This value indicates the maximum current of the equipment when the type-III subrack is used.

Table 4 Climatic conditions for storage

Item                                                     Range

Altitude                                                ≤ 4850 m

Air pressure                                       55 kPa to 106 kPa

Air temperature                                 -40°C to +70°C

Rate of change of temperature     ≤ 1 °C/min

Relative humidity                              5% to 100%

More blog:

How to Troubleshoot Synchronous Ethernet Clocks For Huawei SDH

Watch out Wavelength Information of the TNF1X40 on the OSN 1800

Cautions for a Protection Switching Failure on the DCP and OLP Board On OSN8800