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MGX 8850 and MGX 8950 Software Configuration Guide, Release 2.1
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PDF Copy of the Cisco MGX 8850 Software Configuration Guide
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About this Manual
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Preparing for Configuration
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Configuring General Switch Features
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Preparing AXSM Cards and Lines for Communication
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Preparing RPM Cards and Lines for Communication
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Provisioning
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Managing PNNI Routes
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Switch Operating Procedures
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Switch Maintenance Procedures
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Viewing and Responding to Alarms
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Downloading and Installing Firmware Updates
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Backup Boot Procedures
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Supporting and Using Additional CLI Access Options
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Glossary
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Cisco MGX 8850 Routing Switch Software Configuration Guide, Release 2.1 Supplement, Migration Feature
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Table Of Contents
The MGX 8850 and MGX 8950 Switches
Planning for Card and Line Redundancy
Planning Standalone AXSM Configurations with Redundant Lines
Planning Redundant AXSM Configurations with Standalone Lines
Planning Redundant AXSM Configurations with Redundant Lines
Guidelines for Creating an IP Address Plan
Preparing for Configuration
This chapter introduces the MGX 8850 and the MGX 8950 multiservice switches and common switch topologies, provides an overview of the configuration process, and presents guidelines for collecting the information you will need to complete the configuration.
The MGX 8850 and MGX 8950 Switches
The MGX 8850 multiservice switch and the MGX 8950 multiservice switch provide support for the following features:
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Permanent Virtual Circuits (PVCs)
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The MGX 8950 switch includes a cell bus to operate the combination of the PXM45 and the new XM60 card, which provides 240 Gbps as opposed to 45 Gbps on the PXM45 in the MGX 8850.
The following table identifies the capabilities supported in the Cisco MGX 8850 and 8950 switches.
Typical Topologies
Release 2.1 of the MGX 8850 and MGX 8950 switches support the following topologies:
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Core Switch
Figure 1-1 shows the switch operating in a core switch topology.
Figure 1-1 Core Switch Topology
In the core switch topology, the switch works with other ATM switches to transfer broadband ATM traffic from one ATM edge device to another. The core acts like a freeway, and the edge devices act like freeway on-ramps.
The MGX 8850 and MGX 8950 switches support the following types of trunks: T1 and E1 (MGX 8850 only), DS3, E3, OC-3, OC-12, OC-48, STM-1, STM-4, and STM-16. Typically, core edge nodes communicate with multiple external nodes over relatively slow broadband trunks such as DS3, OC-3, and STM-1 trunks. The internal core node communicates with other core nodes using relatively fast links such as OC-12, OC-48, and STM-16 trunks.
Multiservice Edge Aggregation
Figure 1-2 shows the switch operating in a multiservice edge aggregation topology.
Figure 1-2 Multiservice Edge Aggregation Topology
In the multiservice edge aggregation topology, the switch is colocated with other ATM equipment and communicates with one or more core switches at remote locations. The switch aggregates the traffic from local ATM devices, and packages it for high-speed communications over the core.
Typically, multiservice edge nodes communicate with colocated ATM devices over relatively slow broadband trunks such as DS3 and E3 trunks. The multiservice edge node communicates with core nodes using relatively fast links such as OC-12, OC-48, and STM-16 trunks.
The MGX 8850 Release 1 node shown in Figure 1-2 is called a feeder node. For instructions on configuring the MGX 8850 Release 2.1 switch to communicate with an MGX 8850 Release 1 feeder node, see "Provisioning AXSM Communication Links."
MGX 8850 and MGX 8950 edge nodes also support virtual trunks as shown in Figure 1-3.
Figure 1-3 Virtual Trunk Topology
A virtual trunk provides a private virtual network path through an independent network such as a public ATM network. Using virtual trunks, Company A can establish a private virtual path between two sites using a public ATM network that supports this feature. From Company A's point of view, they have a private virtual path between the two sites that can support multiple virtual circuits (VCs). Company A's network topology is completely private, as all communications are simply passed between edge devices, with no need for translation or routing. To accomplish this, the virtual trunk supports the Service Specific Connection Oriented Protocol (SSCOP) (virtual channel identifier [VCI=5]), Private Network-to-Network Interface (PNNI) (VCI=18) and Integrated Local Management Interface (ILMI) (VCI=16) signaling protocols.
Figure 1-3 shows two virtual trunks, Virtual Trunk A and Virtual Trunk B. At Private Switch A, both virtual trunks use the same line to connect to the core ATM network. Within the core ATM network, Soft Virtual Permanent Paths (SPVPs) are defined to enable direct communications between the core edge nodes. The result is that Private Switch A has virtual trunks to Private Switches B and C and communicates with them as though they were directly connected.
DSL Aggregation
Figure 1-4 shows the switch operating in a Digital Subscriber Link (DSL) edge aggregation topology.
Figure 1-4 DSL Edge Aggregation Topology
In the DSL edge aggregation topology, the switch is colocated with Digital Subscriber Line Access Multiplexers (DSLAMs) and communicates with one or more core switches at remote locations. The switch aggregates the DSL traffic from multiple DSLAMs and packages it for high-speed communications over the core.
Typically, DSL edge nodes communicate with colocated DSLAMs over relatively slower broadband trunks such as DS3 and E3 trunks. The DSL edge node communicates with core nodes using relatively faster links such as OC-3, OC-12, and OC-48 trunks.
Routing Technologies
This release of the MGX 8850 and MGX 8950 switches supports both Private Network-to-Network Interface (PNNI) and Multiprotocol Label Switching (MPLS) routing. These protocols can be used simultaneously on the same switch and on the same link.
Configuration Tasks
Switch configuration is easier if you are familiar with the overall configuration process. To configure and start up the switch, you need to do some or all of the following:
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This chapter describes how to collect or create the information you need to complete these tasks. These tasks are described in the following chapters:
"Configuring General Switch Features," describes how to set up general switch features such as the date, the PNNI controller, and network management. You need to follow the procedures in this chapter to prepare your switch for general operation.
"Preparing AXSM Cards and Lines for Communication," describes how to configure card and line redundancy, and how to bring up lines for physical layer communications.
"Preparing RPM-PR Cards for Operation," describes how to initialize RPM cards and configure card redundancy to support of MPLS routing and communications.
"Provisioning AXSM Communication Links," describes how to configure ATM communications on ATM Switching Service Module (AXSM) lines and how to configure different types of connections to other ATM devices.
For instructions on configuring different ways to manage the MGX 8850 and MGX 8950 switches, see "Supporting and Using Additional CLI Access Options."
Collecting Information
To successfully configure the MGX 8850 and MGX 8950 switches, you must collect information about the other devices to which it will connect. Also, you need to know the line speeds and protocols used on the trunks that connect to the switch. For PNNI routing, you also need to have an addressing plan for the network in which the switch is installed. This information can be grouped into the following categories:
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The following sections introduce these types of data and provide guidelines for collecting the data.
General Configuration Data
During configuration, you will need to enter general configuration data that describes the switch and how it will be used in the network. This data includes
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The following sections describe these topics in more detail.
Unique Switch Name
Each switch must have its own name (which consists of up to 32 characters), unique within the ATM network. If you are adding a switch to a network, find out if the network administrator has established switch naming conventions, and find out which names have already been used. It is a good practice to name switches according to location, as such names convey both the switch identity and its location. The procedure for setting the name is described in "Setting and Viewing the Switch Name" in "Configuring General Switch Features."
ATM Addressing Plan
An ATM network addressing plan is critical for successful operation of the MGX 8850 and MGX 8950 switches in an ATM network. Both MPLS and PNNI networks require unique ATM addresses on each switch. However, the PNNI protocol uses structured network addresses to logically group network devices and determine routes between devices. For PNNI networks, an ATM address plan is required.
PNNI network addressing is described in the Cisco MGX and SES PNNI Network Planning Guide.
IP Addressing Plan
An IP network addressing plan is required for switch management. IP network addressing is described in "Guidelines for Creating an IP Address Plan," later in this chapter.
Administrator Data
In most cases, more than one administrator will manage the switch. The MGX 8850 and MGX 8950 switches support multiple administrators and several different administration levels. As part of the planning process, you might want to identify who will be managing the switch and at what level. You can learn more about managing administrators by reading "Configuring User Access" in "Configuring General Switch Features."
Network Clock Source Plan
Clock synchronization in an ATM network is very important. If two switches have trouble synchronizing their communications, traffic between the switches may slow down or stop. Figure 1-5 shows an example network clock source topology.
Figure 1-5 Example Network Clock Source Topology with a Single Master Clock Source
In Figure 1-5, Switch 1 provides the master network clock source to the rest of the network and uses highly accurate external Building Integrated Timing System (BITS) clock sources to time its transmissions. These BITS clock sources are T1 or E1 lines with stratum 1, 2, or 3 clock signals. Switch 1 uses one BITS line as the primary clock source and uses the secondary BITS source only if a failure occurs on the primary BITS line. If the primary BITS line fails and recovers, the switch reverts to the primary clock source.
Switches 2 through 5 synchronize their transmissions to Switch 1 with the master clock signal, which they receive over AXSM lines. Switch 6 synchronizes its communications using the master clock source, which is forwarded from Switch 3. In this topology, all switches synchronize to the same clock source, and this configuration reduces the possibility that two switches might not be able to synchronize communications.
Figure 1-6 shows an example network clock source topology that uses two master clock sources.
Figure 1-6 Example Network Clock Source Topology with Two Master Clock Sources
In Figure 1-6, Switches 1 and 2 both use BITS clock sources. Switch 1 operates as the master and distributes its BITS clock source over AXSM lines to Switches 2 through 4. Switch 2 is the standby master and receives its primary clock signal over the AXSM line from Switch 1. As long Switch 1 and its primary BITS clock source are operating correctly, the entire network is synchronized to the BITS clock source from Switch 1.
In this example, the secondary clock source for Switch 2 is its BITS clock source, and all other switches are configured to use the AXSM lines from Switch 2 as their secondary clock source. If Switch 1 or its BITS clock source fails, all the switches, including Switch 1, start using the clock signals from Switch 2 for network communications. This configuration preserves network sychronization when either a clock source or a switch fails.
To develop a network clock source plan, create a topology drawing and identify which switches serve as active and standby master clock sources. For each switch that receives clock sources from other switches, indicate which lines carry the primary and secondary clock signals.
When creating your network clock source plan, consider the following:
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Network Management Plan
You can use the following tools to manage the Cisco MGX 8850 and MGX 8950 switches:
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The CLI that comes with the switch is the least expensive option. To use the other tools, you must purchase Cisco WAN Manager (CWM) or a Simple Network Management Protocol (SNMP) manager. The MGX 8850 and MGX 8950 switches come with an SNMP agent for use with an SNMP manager.
The advantage to using CWM or an SNMP manager is that you can use one program to simultaneously manage multiple devices. Also, CWM is the only management tool that can configure Service Class Templates (SCTs), which are described in "Provisioning AXSM Communication Links." Most installations require at least one CWM workstation to complete the switch configuration.
Cisco View is a CWM component that can be used independently of CWM to provide limited monitoring and management capabilities.
To determine which versions of CWM and Cisco View are compatible with this release, refer to the Release Notes for Cisco MGX 8850 Software Version 2.1.60 or the Release Notes for Cisco MGX 8950 Software Version 2.1.60.
For information on managing the switch with an SNMP manager, refer to the following: Cisco MGX 8850 and MGX 8950 SNMP Reference, Release 2.1.
Line and Trunk Data
When configuring lines and trunks that connect the switch to other devices, you need to collect the following:
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The MGX 8850 and MGX 8950 switches support many of the most common ATM configuration parameters. To successfully configure lines and trunks, be sure that the configuration settings used on the switch match the configuration settings used at the other end of the line or trunk. In some cases, options you want to use at one end of the trunk are not supported at the other end. In these situations, change your configuration plan to use settings that are supported at both ends.
"Preparing AXSM Cards and Lines for Communication," describes how to configure physical layer line communications. "Provisioning AXSM Communication Links," describes how to configure ATM ports.
Planning for Card and Line Redundancy
Card redundancy is a feature that associates two cards, so that if one card fails, the other card assumes operation. Processor Switch Module 45 (PXM45) card redundancy is preconfigured on the MGX 8850 and MGX 8950 switches for PXM45 and PXM45/B cards. If PXM45 cards and their associated back cards are inserted in slots 7 and 8, they will automatically operate as redundant cards. One card assumes the active role, and the other card operates in standby mode.
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AXSM cards and their associated lines can be configured for either standalone or redundant operation. Because a configuration change interrupts service and can require substantial configuration teardown, it is important to develop a redundancy plan early. The redundancy plan determines how AXSM cards must be installed in the chassis, and how lines must connect to the cards. Once the hardware is installed, the software configuration team uses the redundancy plan to configure the switch. The software configuration must match the hardware configuration.
RPM-PR cards can operate in 1:n redundancy mode, which means that one standby RPM-PR card can serve as a backup card for multiple active RPM-PR cards.
The MGX 8850 and MGX 8950 switches support the following card and line redundancy options:
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The following sections provide planning guidelines for these configurations.
Planning Standalone AXSM Configurations with Redundant Lines
AXSM cards can operate in either standalone or redundant mode. Standalone mode is the default mode, and standalone cards can be configured for either standalone line operation or Automatic Protection Switching (APS) line operation, which uses redundant lines for fault tolerance. If a standalone AXSM card fails, all calls are lost and the associated lines go out of service. However, if the AXSM card is configured to support redundant lines, a failure on the working line causes a switchover to the protected line, and operation continues.
Figure 1-7 shows how a single AXSM card connects to redundant lines.
Figure 1-7 Standalone AXSM Configuration with Redundant Lines
The redundant lines shown in Figure 1-7 are labeled the working line and the protection line, as defined in the SONET specification for APS. The working line is the primary communications line, and the protection line takes over if the working line fails. If the protection line is being used for traffic and fails, the working line takes over.
Two types of APS communications are supported: 1+1 and 1:1. The 1+1 communications type transmits data on both the working line and the protection line. The 1:1 communications type transmits data on either the working line or the protection line.
Notice that both the working line and the protection line connect to the same back card in Figure 1-7. This configuration is also known as an intracard APS configuration. When planning an intracard APS configuration, consider the following:
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Planning Redundant AXSM Configurations with Standalone Lines
In a redundant AXSM configuration, matched sets of front and back cards are installed in the switch, and redundancy is established during software configuration. In a redundant AXSM configuration, a failure on the active AXSM front card causes a switchover to the standby AXSM card set, and no calls are lost.
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Figure 1-8 shows how a redundant AXSM cards connect to standalone lines.
Figure 1-8 Redundant AXSM Configuration with Standalone Lines
Figure 1-8 shows two complete sets of AXSM cards. Each port in an active card slot is connected to the corresponding port in the standby card slot through a Y-cable, which joins the two ports to a common line. If the front card in the active card set fails, the standby card set becomes active and continues to support calls over the shared communication line.
When planning a redundant AXSM configuration with a standalone line, consider the following:
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Planning Redundant AXSM Configurations with Redundant Lines
Maximum fault tolerance is achieved when redundant AXSM cards are used with redundant APS lines. In this configuration, fault tolerance is provided for the front card and for the combination of the back card and the communication line. If the active line or the back card to which it is connected fails, communications traffic is rerouted through the backup line and the back card to which it is connected.
Figure 1-9 shows how a redundant AXSM card connects to redundant APS lines.
Figure 1-9 Redundant AXSM Configuration with Redundant Lines
Figure 1-9 shows two complete sets of AXSM cards. Each port in each card slot connects to an independent line. If the front card in the active card set fails, the standby card set becomes active and continues to support calls over the shared communication line. If the working line fails, communications are rerouted through the protection line for that port.
When planning a redundant AXSM configuration with a redundant lines, consider the following:
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Configuration Worksheets
Table 1-2 lists general switch parameters you will need to configure in each new switch.
Table 1-3 lists general switch parameters you will need to configure on each AXSM card.
Guidelines for Creating an IP Address Plan
The switch provides the following interfaces for CLI, SNMP, and CWM access:
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Basic switch configuration and management can be completed by using a local terminal connected to the console port. However, to configure and manage the switch from a LAN connection, a modem connection, or with CWM, you need define an IP address for the appropriate interface.
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A typical switch configuration requires either one or two IP addresses for LAN access. When the switch hosts a single PXM45 card, use just one IP address and assign it to both the boot and LAN IP address options (more on this later in this section). When the switch uses two PXM45 cards, you can choose to use one or two IP addresses. Figure 1-10 shows a redundant PXM45 configuration that uses two IP addresses.
Figure 1-10 Using Multiple IP Addresses for Switch Access
The configuration shown in Figure 1-10 provides the following benefits:
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When different IP addresses are used for the boot and LAN IP addresses, you can manage the active PXM45 card and the switch using the LAN or disk IP address, which is B.B.B.B in Figure 1-10. You can also access the standby PXM45 card using the boot IP address. When the same address is used for both the boot and LAN IP addresses, that address can be used only to manage the active PXM45 card.
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When planning IP addresses for your switch, use the following guidelines:
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For instructions on setting boot and LAN IP addresses, refer to "Setting the LAN IP Addresses" in "Configuring General Switch Features."
