Table Of Contents
Cisco ONS 15327 Product Overview
Note The terms "Unidirectional Path Switched Ring" and "UPSR" may appear in Cisco literature. These terms do not refer to using Cisco ONS 15xxx products in a unidirectional path switched ring configuration. Rather, these terms, as well as "Path Protected Mesh Network" and "PPMN," refer generally to Cisco's path protection feature, which may be used in any topological network configuration. Cisco does not recommend using its path protection feature in any particular topological network configuration.
The Cisco ONS 15327 provides efficient bandwidth delivery and management in optical transport networks. Like the larger Cisco ONS 15454,the ONS 15327 is a SONET add/drop multiplexer that offers service aggregation and high-bandwidth transport of voice and data traffic on a single platform. This smaller footprint makes the ONS 15327 cost-effective and space-efficient when the full capability of the ONS 15454 is not required, while still enabling users to easily manage services and quickly increase capacity without disrupting service. The ONS 15327 is ideal for extending the edge of the optical network to the customer premise.
Figure 1 Cisco ONS 15327
The ONS 15327 is designed for maximum flexibility. It carries traditional time-division multiplexing (TDM) and high-speed data traffic — a variety of card configurations offer incremental bandwidth increases as needed and support DS-1, DS-3, OC-3, OC-12, OC-48, and 10/100 Ethernet and Gigabit Ethernet speeds. Cisco Transport Controller (CTC), the ONS 15327 software interface, provides easy card, node, and network-level provisioning. The ONS 15327 deploys a variety of network configurations, including terminal mode (TM), linear add/drop multiplexer (ADM), bidirectional line switched ring (BLSR), path protection, subtending rings, and path-protected mesh network (PPMN). The ONS 15327 can be combined with ONS 15454s in any network configuration.
Common Control Cards
The ONS 15327 has eight card slots numbered 1- 8; four traffic slots, two Cross-Connect, Timing, and Control (XTC) slots, and two Mechanical Interface card (MIC) slots.
Figure 2 ONS 15327 Showing Card Slot Types
All slots are card-ready, meaning that when you plug in a card it automatically boots up and becomes ready for service. The cards offer bandwidth in modular increments, making it cost-effective to deploy the system in low-density applications and add bandwidth as needed. The ONS 15327 houses four types of cards: XTC (common control), MIC, Optical, and Ethernet. The XTC cards and MICs provide electrical interfaces (DS-1 and DS-3).
Figure 3 ONS 15327 Card Slot Numbers
The XTC is the common-control card for the ONS 15327 and contains the electrical tributary circuitry for connecting DS-N traffic. The ONS 15327 provides two XTC cards. The XTC-28-3 card supports 28 DS-1s and three DS-3s.
Figure 4 XTC 28-3 Card Faceplate
The XTC-14 card supports 14 DS-1s.
Figure 5 XTC-14 Card Faceplate
Timing and Control Functions
The XTC houses the central intelligence of the ONS 15327 and combines timing, control, and switching functions. It performs:
•IP address detection and resolution
•Timing, compliant with Telcordia requirements
•SONET data communications channel (DCC) termination
•System fault detection
•Cross-connect maintenance and management
The CRIT, MAJ, MIN, and REM alarm LEDs on the XTC faceplate indicate whether a Critical, Major, Minor, or Remote alarm is present anywhere on the ONS 15327 or on a remote node in the network.
The XTC card establishes connections and performs time-division switching (TDS) at the STS-1 level between ONS 15327 traffic cards. You can concentrate or groom low-speed traffic from line cards onto high-speed transport spans and drop low-speed traffic from transport spans onto line cards. The XTC cards provide performance monitoring and protection switching and support STS and VT-level grooming. Slots 5 and 6 are the XTC slots.
In-Service Software Upgrade
The node name, configuration database, IP address, and software are stored in the XTC card's non-volatile memory, which allows quick recovery if power or card failures occur. You can upgrade the software without affecting traffic on the ONS 15327 if dual XTC cards are used.
You can use the reinitialization (reinit) tool to clear the XTC database and restore customer or factory defaults. This process involves uploading the most recent software package and a blank database. The reinit tool is a .jar file available from the software CD.
Mechanical Interface Cards
The two MICs, MIC-28-3-A and MIC-28-3-B, provide the physical connection points for the DS-1 and DS-3 interfaces on the XTC cards. They also provide redundant power inputs, inputs and outputs for user-provisionable alarms and controls, and a Building Integrating Timing Supply (BITS) timing input and output.
Each MIC provides 14 DS-1 interfaces for a total of 28 DS-1 interfaces; combined, the MICs provide three DS-3 interfaces.
Figure 6 MIC-28-3-A Faceplate
Because the three transmit (Tx) interfaces are on MIC-28-3-A and the three receive (Rx) interfaces are on MIC-28-3-B, you must install both MICs to use the DS-3 capabilities of the ONS 15327.
Figure 7 MIC-28-3-B Faceplate
The electrical tributary circuitry for managing individual DS-1s and DS-3s resides in the XTC cards; therefore, you must provision DS-1 and DS-3 circuits using the XTC card.
Each MIC has three input contacts and one output contact. These contacts provide up to six external input alarms and two external output controls that you can provision in CTC. Each MIC also provides connection for one BITS clock input and one BITS clock output. Slots 7 and 8 are the MIC slots.
The optical cards, OC3 IR 4 1310, OC12 IR 1310, OC12 LR 1550, OC48 IR 1310 and OC48 LR 1550, can reside in any traffic card slot (1 - 4). You can provision an optical card as part of a path protection or, in ADM/TM configurations, as either an access tributary or a transport span interface. OC-12 and OC-48 cards can support a two-fiber BLSR.
OC3 IR 4 1310 Card
The OC3 IR 4 1310 card provides four intermediate-reach, Telcordia-compliant, GR-253 SONET OC-3 interfaces per card. The interface operates at 155.52 Mbps over a single-mode fiber span and supports VT payloads and non-concatenated or concatenated payloads for STS-1 or STS-3c.
OC12 IR 1310 Card
The OC12 IR 1310 card provides one intermediate or short-range, Telcordia-compliant, GR-253 SONET OC-12 interface. The interface operates at 622.08 Mbps over a single-mode fiber span and supports VT payloads and non-concatenated or concatenated payloads of STS-1, STS-3c, STS-6c, or STS-12c.
OC12 LR 1550 Card
The OC12 LR 1550 card provides one long-reach, Telcordia-compliant, GR-253 SONET OC-12 interface per card. The interface operates at 622.08 Mbps over a single-mode fiber span and supports VT payloads and non-concatenated or concatenated payloads of STS-1, STS-3c, STS-6c, or STS-12c.
OC48 IR 1310 Card
The OC48 IR 1310 card provides one intermediate-range, Telcordia-compliant, GR-253 SONET OC-48 interface. Each interface operates at 2488.320 Mbps over a single-mode fiber span and supports VT payloads and non-concatenated or concatenated payloads of STS-1, STS-3c, STS-6c, STS-12c, or STS-48c.
OC48 LR 1550 Card
The OC48 LR 1550 card provides one intermediate-reach, Telcordia-compliant, GR-253 SONET OC-48 interface per card. Each interface operates at 2488.320 Mbps over a single-mode fiber span and supports VT payloads and non-concatenated or concatenated payloads of STS-1, STS-3c, STS-6c, STS-12c, or STS-48c.
The Ethernet cards eliminate the need for external Ethernet aggregation equipment and provide efficient transport and co-existence of traditional TDM traffic with packet-switched data traffic. Multiple Ethernet cards installed in an ONS 15327 can operate independently or act as a single switch (EtherSwitch) supporting a variety of SONET port configurations.
The E10/100-4 card provides four IEEE 802.3-compliant, 10/100 interfaces. Each interface supports full-duplex operation for a maximum bandwidth of 200 Mbps per port and 622 Mbps per card. Each port can independently detect the speed of an attached device (auto-senses) and automatically connects at the appropriate speed. The ports auto-configure to operate at either half or full duplex and can determine whether to enable or disable flow control.
The G1000-2 provides two IEEE 802.3-compliant, 1000 Mbps ports for high-capacity customer LAN interconnections. Each port supports full-duplex operation for a maximum bandwidth of 2000 Mbps per port. The G1000-2 card uses standard small-form-factor pluggable (SFP) modules for the optical ports. SFPs are input/output devices that p lug into a Gigabit Ethernet port to link the port to the fiber-optic network. Cisco provides two SFP modules: one for short-reach applications and one for long-reach applications. The short-reach model connects to multimode fiber and the long-reach model requires single-mode fiber.
The ONS 15327 provides 1:1 electrical protection and 1+1 optical protection methods. 1:1 electrical protection is pre-provisioned for DS-1 and DS-3 traffic; therefore, only optical cards can operate unprotected.
Both XTC cards provide circuitry and electrical protection for DS-1 circuits, but only the XTC-28-3 card provides circuitry and electrical protection for DS-3 circuits. On the ONS 15327, DS-N circuits are automatically protected by a 1:1 protection group, named XTCPROTGRP, which you cannot edit or delete. In 1:1 protection, a working card is paired with an adjacent protect card of the same type, which for the ONS 15327 is two XTC-14 cards (DS-1 circuits protected) or two XTC-28-14 cards (DS-1 and DS-3 circuits protected). If the working card fails, the traffic from the working card switches to the protect card. Electrical protection in the ONS 15327 is non-revertive.
Optical Card Protection
The ONS 15327 supports 1+1 protection to create redundancy for optical cards. With 1+1 protection, one optical port can protect another optical port; therefore, in any two slots a single working card and a single dedicated protect card of the same type (for example, two OC-48 cards) can be paired for protection. If the working card fails, the protect card takes over. 1+1 span protection can be either revertive or non-revertive.
Cisco Transport Controller
Cisco Transport Controller (CTC) is a software program that is automatically downloaded from the XTC card to your computer when you connect to the ONS 15327. CTC gives you control of Operation, Administration, Maintenance, and Provisioning (OAM&P) activities for the ONS 15327 using Netscape Navigator or Microsoft Internet Explorer.
Graphical User Interface
The CTC graphical user interface (GUI), also called the CTC window, provides three primary views, or modes, that include:
•Network View-Provides information about the ONS 15327 network and displays a map with ONS 15327 nodes represented by colored icons. You can install a custom map for the network view, create domains that group several nodes into a single icon for a clearer display, and create a network view that will be shared by all nodes on a network.
•Node View-displayed each time you log into CTC, this view provides information about the node and displays a graphic of the ONS 15327 shelf. The cards are color-coded to show the status of the physical cards and ports.
•Card View-provides information about individual ONS 15327 cards and displays a graphic of the selected card. The information that displays and the tasks you can perform depend on the card.
The CTC GUI displays text fields with tabs to use for navigation. Some CTC tabs have subtabs, which are used to access subfunctions. From the tabs you can perform all the OAM&P tasks, such as provisioning cards, rings, and circuits; creating protection groups; setting timing parameters; viewing and clearing alarms; provisioning DCCs; backing up and restoring the database; and troubleshooting, including creating diagnostic files and performing loopbacks.
Figure 8 shows the CTC GUI.
Figure 8 CTC GUI (window) in Network View
Proxy Server Features
The proxy server feature set allows CTC to access ONS 15327s while restricting unauthorized IP connectivity. It can also be used to reduce the amount of network provisioning required for external routers and CTC workstations.
The proxy server feature set consists of the following:
•Automatic host detection—Also known as ARP sniffing, this feature allows a CTC workstation on a different subnet than the target ONS 15327 to directly connect and launch CTC.
•Proxy server—When this feature is enabled, one ONS 15327 will act like a as a network proxy for other DCC-connected nodes that do not have direct IP connectivity.
•Firewall—When this feature is enabled, certain IP communications are restricted between an ONS 15327 SDCC channels and the XTC card Ethernet port. This prevents CTC workstations from using the ONS 15327 SDCC communication path to access other workstations on the data communications network.
•Craft Access Only—When this feature is enabled, multiple CTC sessions on the same subnet are allowed without the need to enter static routes.
Users and Security
You can add up to 500 users to one ONS 15327.
Each ONS 15327 user is assigned one of the following security levels:
•Retrieve—This user can retrieve and view CTC information but cannot set or modify parameters.
•Maintenance—This user can access only the ONS 15327 maintenance options.
•Provisioning—This user can access provisioning and maintenance options.
•Superuser—This user can perform all of the functions of the other security levels. They can also set names, passwords, and security levels for other users.
CTC provides provisionable settings to enhance security. Superusers can:
•Limit a particular user ID to a single login occurrence.
•Limit the number of failed login attempts per node and per user.
•Set the length of user timeouts on an individual node or for all nodes controlled by the CTC session.
•View a list of currently logged in users.
•Receive automatic notifications of user login activity for users logged in through TL1 or CTC.
•View a user's
–last successful login
–number of unsuccessful login attempts since the last successful login
–status (logged in or out, locked out)
•Log out another user from CTC who is actively logged in (through CTC or TL1). The user is notified of the forcible lockout.
•Lock out a user and specify the lockout duration.
•Delete a user and choose to immediately log off that user.
•Delete other Superusers (one Superuser ID must remain).
•Suppress the IP address on the LCD panel and/or CTC.
CTC employs password complexity rules to enhance login security:
•The user ID and password cannot be identical, nor can the password contain the sequence of characters used in the user ID.
•Newly created passwords must comply with Telcordia GR-815, which requires that passwords be at least 6 characters long, and contain at least one alphabetic character, one numeric character, and one special character (+, #, or %).
•You can provision a waiting period and number of previous password values to prevent the current password value from being identical to a previous value.
Circuit Provisioning and Management
CTC enables automated circuit provisioning across ONS 15327 subnetworks and between ONS 15327s and ONS 15454s, including STS, VT1.5, multiple drop, monitor, and Ethernet circuits. From the CTC GUI, you select a source ONS 15327 and a destination ONS 15327 to create an end-to-end circuit.
Figure 9 Creating Circuits With the CTC Circuit Creation Dialog Box
The ONS 15327 automatically calculates the best path and STS/VT to use between these two nodes. It sets up all the cross-connects in each of the ONS 15327 nodes along the circuit path. You can select the circuit type, bidirectional or unidirectional status, circuit size, and whether path-protected traffic is required. You can also route circuits manually, for example to force traffic onto a particular path. See the "Ethernet" section for a description of Ethernet circuits.
CTC provides an auto-range feature that automatically creates sequential circuits, which prevents you from needing to individually build circuits of the same type. Specify the number of circuits you need, create one circuit, and CTC automatically creates additional sequential circuits.
Detailed Circuit Map
The detailed circuit map provides an end-to-end view of circuits rather than simply nodes and their spans. Specifically the circuit map shows ports, drops, spans, and selectors for path protection circuits.
Protection Channel Access
With Protection Channel Access (PCA), you can create circuits that use the idle protection bandwidth available on BLSRs. PCA circuits are preempted when a protection switch occurs and are restored after the provisioned wait-to-restore time is exceeded.
Enhanced Circuit States
State is a user-assigned designation to indicate whether the circuit should be in or out of service. You can assign the following states to circuits and ports:
•IS—In service; able to carry traffic.
•OOS—Out of service; unable to carry traffic.
•OOS-AINS—Out of service, auto inservice; will change to IS when a signal is received. Traffic is carried, but alarms are suppressed and loopbacks are allowed.
•OOS-MT—Out of service, maintenance. Traffic is carried, but alarms are suppressed and loopbacks are allowed.
To carry traffic, circuits must have a status of Active and a state of IS, OOS_AINS, or OOS_MT, and the circuit source and destination ports must also be IS, OOS_AINS, or OOS_MT. PARTIAL is appended to a circuit state whenever all circuit cross connects are not in the same state.
Testing and verifying circuit integrity often involves taking down the whole line; however, with the Release 4.0 cross-connect loopback, you can create a loopback on any embedded channel at supported payloads at the STS-1 granularity and higher. For example, you can loop back a single STS-1, STS-3c, STS-6c, etc. on an optical facility without interrupting the other STS circuits. Cross-connect loopbacks are supported for optical cards.
CTC displays section, line, and path performance monitoring for optical, electrical, and Ethernet statistics, as defined in GR-253-CORE and GR-820-CORE. For each statistic, you can display 31 previous 15-minute intervals and the current 15-minute interval, as well as the previous 24-hour and current 24-hour interval.
In Release 4.0, when traffic is switched from the working to the protection span, standard SONET and SDH Near End Path PM values are available over the protection span in the 2-fiber and 4-fiber BLSR.
In-Service Span Upgrades
The CTC Span Upgrade Wizard allows you to upgrade the optical fiber connection between two ONS 15327 nodes. The transmission rate of a span is upgraded from a lower to a higher OC-N signal but all other span configuration attributes remain unchanged. With multiple nodes, a span upgrade is a coordinated series of upgrades on all nodes in the ring or protection group in which traffic carried at a lower OC-N rate is transferred to a higher OC-N. You can use perform in-service span upgrades for the following ONS 15327 cards:
•OC-12 IR to OC-12 LR
•OC-12 to OC-48
•OC-48 IR to OC-48 LR
The ONS 15327 offers network management flexibility. In CTC you can choose to see the login node, nodes with DCC-connectivity to the login node, and nodes that are not DCC-connected to the node.
The ONS 15327 uses SONET data communication channels (SDCCs) for CTC connectivity, automated circuit provisioning, and alarm reporting from remote nodes. Using a node's SDCC, CTC automatically finds and recognizes other ONS 15327s. However, during login you can choose to exclude DCC-connected nodes from auto-discovery, which speeds up login time and reduces clutter on the network map.
Login Node Groups
When you log into an ONS 15327 node, only ONS 15327s with DCC connectivity to the node are autodiscovered and displayed in network view. However, you can create a login node group to view and manage ONS 15327s that have an IP connection but no DCC-connectivity to the login node.
For example, in Figure 10, if you logged into Node 1 you would see Node 2 and Node 3 because they have DCC connectivity to Node 1. You would not see Nodes 4, 5, and 6 because DCC connections do not exist. To view all six nodes at once, create a login node group with the IP addresses of Nodes 1, 4, and 5. Those nodes, and all nodes optically connected to them, will display when you log into any node in the group.
Figure 10 Viewing Non-DCC Nodes Using a Login Node Group
Network Element Defaults
Traffic cards in the ONS 15327 are preprovisioned with default line and threshold standards that are compliant with Telcordia recommendations. You can use CTC to change these settings on a port or card basis. To override the defaults, the ONS 15327 provides a network element (NE) defaults editor to override and configure the default value settings at the port or card level. Default values can be changed, exported, imported, and applied using an ASCII text file. Any changes to card defaults do not affect previous provisioning; only entities created after you make the change are affected by the new defaults. Node-level changes take effect immediately.
Alarm Collection and Display
The XTCs have faceplate LEDs that alert you to alarms and provide the critical, major, or minor status of the alarm. CTC displays alarms and events on a card or node level for all ONS 15327s in the network. You can also view all alarm messages that appear in CTC using TL1.
Alarms are displayed in one of five background colors to quickly communicate the alarm severity. You can control the display of current and cleared alarms generated on the node. The alarm and event screens include date, time, severity, reporting node, reporting object, service-affecting status, and a description.
Figure 11 Viewing Alarms on the CTC Alarm Window
The history feature displays historical alarm data and also shows events (non-reported activities) that have occurred, such as performance monitoring threshold crossings or protection switching events. The CTC History tab uses subtabs to present two alarm history views:
•The Session subtab presents alarms and events for the current CTC session. When you log off, the alarms disappear.
•The Node subtab shows the alarms and events that occurred at the node since the CTC software installation. The ONS 15327 can store up to 256 critical alarms, 256 major alarms, 256 minor alarms, and 256 events. When the limit is reached, the ONS 15327 discards the oldest alarms and events.
The alarm profile feature allows you to change the default alarm severities (for example, change an alarm severity from minor to major) and apply the new severities at the port, card, node, or network level.
Every alarm has a default profile. To create a new profile, clone the default in CTC, rename it, and choose the severity settings for the new profile. Activating and changing profiles are simple procedures in CTC.
CTC supports severity-based filtering for alarms, conditions, and event history. for any severity. Alarm filtering is enabled in the card, node, and network views of the same window for all nodes in the network. For example, if the filter tool is enabled in the node view Alarms window, the network view Alarms window and card view Alarms window also show the tool enabled.
You can also provision a snapshot period during which filtered alarms will show through the filter.
You can prevent alarms from appearing in the CTC Alarms window on a port, card, or node basis. This feature is useful, for example, in circumstances when an alarm or condition is known to exist but you do not want to include it in the display.
Visual and audible alarms are typically wired to trigger an alarm light or sound at a central alarm collection point when the corresponding contacts are closed. The alarm cutoff (ACO) function stops (turns off) the transmission of the alarm signal to the alarm collection point. To activate the ACO function, press the ACO button on the XTC card faceplate. The ACO button clears all audible alarm indications. The alarm is still active in CTC and needs to be cleared.
With the XTC card-level view in CTC, you can also suppress alarms for a specific DS-1 or DS-3 port. Using CTC you can also suppress alarms for specific optical and Ethernet ports.
User-Provisionable External Alarms and Controls
In addition to the standard alarms, the ONS 15327 provides user-provisionable alarms and controls. You can provision up to six external alarm inputs and two external controls. Use external alarms for open doors, temperature sensors, flood sensors, and other environmental conditions. For each alarm you can specify type, severity, and a description. Use external controls, or office alarms, to drive visual or audible devices such as bells and lights. The alarm-triggering conditions for the external controls can be user-defined external input alarms, remote alarms, or severity-based alarms (for example, alarms that trigger when any Major alarm happens).
Figure 12 shows a diagram of the input and output process for external alarms and controls.
Figure 12 External Alarm Input and Output
Provisioning external alarms and controls provides a "virtual wires" option that you can use to route alarms and controls from different nodes to one or more alarm collection centers. For example, in Figure 13, smoke detectors are provisioned as external alarms at Nodes 1, 2, 3, and 4. The alarms are assigned to Virtual Wire 1, and Virtual Wire 1 is provisioned as the trigger (control) for an external bell at Node 1.
Figure 13 External Alarms and Controls Using a Virtual Wire Configuration
The XTC card performs all system-timing functions for each ONS 15327. The XTC card selects a recovered clock, a BITS, or an internal Stratum 3 reference as the system-timing reference. You can provision any of the clock inputs as a primary or secondary timing source. If you identify two timing references, the secondary reference provides protection. A slow-reference tracking loop allows the XTC card to synchronize to the recovered clock, which provides holdover if the reference is lost.
You must set the SONET timing parameters for each ONS 15327. ONS 15327 timing is set to one of two modes: external or line. An externally-timed node derives its timing from a BITS source wired to the BITS input on the MIC. The BITS source, in turn, derives its timing from a Primary Reference Source (PRS) such as a Stratum 1 clock or GPS signal. A line-timed node derives its timing for an incoming optical signal on one of the optical line cards.
Synchronization Status Messaging
Synchronization status messaging (SSM) is a mechanism for managing synchronization (or network timing) in SONET networks. It allows BITS timing sources, nodes, and combinations of the two to exchange information about the quality of timing sources. SSM enables SONET devices such as the ONS 15327 to automatically select the highest quality timing reference and to avoid timing loops (particularly in ring architecture). Synchronization status messages are carried in the S1 byte of the SONET line overhead (Line layer) and as a bit-patterned message in the Extended Super Frame (ESF) datalink of the BITS DS-1. The ONS 15327 supports BITS inputs with or without SSM.
To maximize Ethernet cost effectiveness, the ONS 15327 integrates Ethernet access into the same SONET platform that transports voice traffic. Ethernet over SONET lets service providers augment TDM services with Ethernet and allows delivery of data traffic over existing facilities. The ONS 15327 supports layer 2 switching and the ability to classify Ethernet traffic as defined in the IEEE 802.1 Q-tag standard. You can switch tagged traffic onto separate SONET STS channels to engineer bandwidth by traffic class. The ONS 15327 can also concentrate Ethernet ports into one or more STS-N circuits to use bandwidth more efficiently.
Figure 14 Ethernet Aggregation and Transport
Networks without priority queuing handle all packets on a first-in-first-out basis. Priority queuing, which is supported by the ONS 15327, reduces the impact of network congestion by mapping Ethernet traffic to different priority levels. The ONS 15327 takes the eight priorities specified in IEEE 802.1Q and maps them to two queues. Q-tags carry priority queuing information through the network.
The ONS 15327 works with Ethernet devices that do and do not support IEEE 802.1Q tagging. The ONS 15327 supports virtual LANs that provide private network service across a SONET backbone. You can define specific Ethernet ports and SONET STS channels as a VLAN group. VLAN groups isolate subscriber traffic from users outside the VLAN group and keep "outside" traffic from "leaking" into the virtual private network (VPN). Each IEEE 802.1Q VLAN represents a different logical network.
Spanning Tree Protocol
The ONS 15327 operates spanning tree protocol (STP) using the IEEE 802.1D Q-tag standard. STP detects and eliminates network loops. When STP detects multiple paths between any two network hosts, STP blocks ports until only one path exists between any two network hosts. The single path eliminates possible bridge loops. You can enable spanning tree at the Ethernet-port level with a simple CTC procedure.
The ONS 15327 has three common methods for configuring Ethernet circuits between ONS nodes: a straight-circuit configuration, a shared packet ring configuration, and a hub-and-spoke configuration. Two nodes usually connect with a straight circuit configuration. More than two nodes usually connect with a shared packet ring or a hub and spoke configuration. You can also manually cross connect individual Ethernet circuits to an STS channel on the ONS 15327 optical interface.
You can also manually cross connect individual Ethernet circuits to an OC-N channel on the ONS 15327 optical interface. You can create a circuit end-to-end between an E-series (in Single-Card EtherSwitch or linear mode) and an EC1 span crossing over two or more nodes (with optical links) when the selected circuit size is STS-1.
Single-Card and Multicard EtherSwitch
The ONS 15327 supports single-card and multicard EtherSwitch for E-Series cards.
When you provision single-card EtherSwitch, each Ethernet card is a single switching entity within the ONS 15327. This option allows STS-12c of bandwidth between two Ethernet circuit points. Single-card EtherSwitch supports one STS-12c, one STS-6c, two STS-3c or six STS-1 circuits. Figure 15 shows a single-card EtherSwitch.
Figure 15 Single-Card EtherSwitch
When you provision multicard EtherSwitch, two or more Ethernet cards act as a single layer 2 switch. Multicard EtherSwitch supports one STS-3c circuit or three STS-1 circuits. The bandwidth of the single switch formed by the Ethernet cards matches the bandwidth of the provisioned Ethernet circuit up to STS-3c bandwidth.Figure 16 shows a multicard EtherSwitch.
Figure 16 Multicard EtherSwitch
E-Series Port-Mapped Mode
Port-mapped mode, also known as linear mapper, is a new operation mode that accompanies the Multicard EtherSwitch Group mode and the Single-Card EtherSwitch mode on each E-Series card starting with Release 4.0.
The benefit of the linear mapper is that it allows Ethernet traffic to be mapped directly onto the SONET/SDH circuit without passing through a layer 2 (L2) switching engine. L2 switching capabilities of E-Series cards provide a much wider range of functionality than a simple L1 Ethernet-to-SONET/SDH mapping scheme.
Ethernet Tx and Rx Utilization
The node view port utilization values for Release 4.0 now separate transmit values from receive values. This affords you a clearer picture of actual utilization levels in this view, even when levels are very small.
The ONS 15327 is compatible with several network management protocols, such as Simple Network Management Protocol (SNMP), Proxy Address Resolution Protocol (ARP), Open Shortest Path First (OSPF) protocol, and Routing Information Protocol (RIP). If OSPF is not available, static routes can also connect to ONS 15327s through routers. DCC tunneling is provided for interoperability with third-party vendor equipment.
Simple Network Management Protocol
Simple Network Management Protocol (SNMP) is an application-layer Internet Protocol (IP) that enables network devices to exchange management information. Network administrators can manage network performance, find and solve network problems, and plan for network growth. The ONS 15327 supports SNMP Version 1 (SNMPv1) and SNMP Version 2c (SNMPv2c); SNMPv2c offers additional protocol operations.
The ONS 15327 uses SNMP to communicate segments of the CTC information model to network management systems, such as HP OpenView Network Node Manager (NNM) or Open Systems Interconnection (OSI) NetExpert. SNMP conveys information required for node-level inventory, fault, and performance management of the ONS 15327 node, and for generic read-only management of DS-1, DS-3, SONET, and Ethernet technologies.
The ONS 15327 incorporates SNMP Remote Monitoring (RMON) to allow network operators to monitor the ONS 15327 E10/100-4 (Ethernet) cards. RMON operates transparently with a network management application, but you can provision RMON alarm thresholds with CTC.
Proxy Address Resolution protocol (ARP) enables a LAN-connected gateway ONS 15327 to automatically handle ARP requests for remote non-LAN ONS 15327s connected by a DCC to the gateway ONS 15327. Proxy ARP requires no manual configuration in CTC.
Proxy ARP has a single LAN-connected ONS 15327 stand in (proxy) for remote ONS 15327s. If a device on the LAN sends an ARP request intended for one of the DCC-connected ONS 15327s, the gateway ONS 15327 returns its own MAC address to the LAN device. The LAN device then sends the datagram intended for the remote ONS 15327 to the MAC address of the proxy ONS 15327. The proxy ONS 15327 forwards this data to the remote 15327 using its own ARP table.
Figure 17 Proxy ARP Example
Open Shortest Path First
If ONS 15327s are connected to Open Shortest Path First (OSPF) networks, ONS 15327 network information can be automatically communicated across multiple LANs and WANs.
OSPF is a link state Internet routing protocol. Link state protocols use a "hello protocol" to monitor their links with adjacent routers and test their links to their neighbors. Link state protocols advertise their directly-connected networks and their active links. Each link state router captures the link state "advertisements" and puts them together to create a topology of the entire network or area. From this database, the router calculates a routing table by constructing a shortest path tree. Routes are continuously recalculated to capture ongoing topology changes.
You can enable OSPF on the ONS 15327s so that the ONS 15327 topology is sent to OSPF routers on a LAN. Advertising the ONS 15327 network topology to LAN routers eliminates the need to manually provision static routes for ONS 15327 subnetworks.
Static Route Provisioning
The ONS 15327 uses CTC to provision static network routes in ONS 15327 network elements (NEs). Static routes make it possible to have multiple CTC sessions, with different destination IP addresses, on a network of ONS 15327s that all lie on the same subnet. For example, a Network Operations Center (NOC) can remotely monitor an ONS 15327 through CTC at the same time that an on-site employee is logged into an ONS 15327 on the network with a separate CTC session. Static routes also allow workstations to connect to ONS 15327s through routers.
You can tunnel third-party SONET equipment DCCs across ONS 15327 networks. A DCC tunnel is a series of connection points that map a third-party equipment DCC to ONS 15327 DCCs. A DCC tunnel end point is defined by the slot, port, and DCC type. To create a DCC tunnel, you connect the tunnel end points from one ONS 15327 optical port to another. DCC traffic is forwarded transparently, byte-for-byte, across the ONS 15327 network.
Routing Information Protocol, Versions 1 and 2
You can enable Routing Information Protocol (RIP) through CTC. RIP, Version 1 (RIP1) sends updates to a broadcast address so that all devices on the LAN receive and process the messages. RIP, Version 2 (RIP2) reduces unnecessary traffic to hosts that do not receive RIP2 messages by enabling the router to only exchange routing information between connected neighbors.
The ONS 15327 supports bidirectional line switched rings (BLSRs), path protection, path protection dual ring interconnects, subtending rings, linear add-drop multiplexer (ADM) and point-to-point configurations supporting 1+1 protection, and mixed configurations. You can also create path-protected mesh networks (PPMNs).
Bidirectional Line Switched Ring
The ONS 15327 supports two-fiber BLSRs with up to 32 ONS 15327 nodes. BLSRs work well for distributed traffic applications, such as interoffice networks.
Two-fiber BLSRs allocate half the available fiber bandwidth for protection. In a two-fiber OC-48 BLSR, for example, STSs 1 through 24 are allocated to working traffic, and STSs 25 through 48 are allocated for protection. If a break occurs on one fiber, working traffic switches to the protection bandwidth (STSs 25 through 48) on the other fiber. Working traffic travels in one direction on STSs 1 through 24 on one fiber, and on STSs 1 through 24 in the opposite direction on the second fiber. You can create OC-12 and OC-48 two-fiber BLSRs. Figure 18 shows an example of a two-fiber BLSR.
Figure 18 Two-Fiber Bidirectional Line Switched Ring
Path Protection Configuration
A path protection is a closed-loop, two-fiber transport architecture that survives cable cuts and equipment failure because it provides duplicate fiber paths for each service. Nodes in the ring are connected using a single pair of optical fibers. Working traffic flows in one direction on the ring and the second fiber provides a protection path flowing in the opposite direction. If a problem occurs in the working traffic path, the receiving node switches to the path coming from the opposite direction.
Services can originate and terminate on the same path protection or can be passed to an adjacent access or interoffice ring for transport to the service-terminating location. Because each traffic path is transported around the entire ring, path protection are best suited for networks where traffic concentrates in one or two locations and is not widely distributed.
Figure 19 shows a basic path protection configuration. If Node ID 0 sends a signal to Node ID 2, the working signal travels on the working traffic path through Node ID 1. The same signal is also sent on the protect traffic path through Node ID 3. If a fiber break occurs, Node ID 2 switches its active receiver to the protect signal coming through Node ID 3.
Figure 19 Unidirectional Path-Switched Ring Example
Path Protection Dual Ring Interconnect
The path protection dual ring interconnect topology (path protection DRI) provides an extra level of path protection between interconnected path protection. In path protection DRIs, traffic is dropped and continued at the interconnecting nodes to eliminate single points of failure. Two DRI topologies can be implemented on the ONS 15327. The traditional DRI uses four ONS 15327s as the interconnect nodes, while the integrated DRI uses two nodes.
Path protection and BLSRs can be subtended from one another using one shared node; the node can terminate and groom any one of the following ring combinations:
•5 path protection, or
•4 path protection and 1 BLSR, or
Subtending rings from an ONS 15327 reduces the number of nodes and cards required, and reduces external shelf-to-shelf cabling. Figure 20 shows an ONS 15327 with multiple subtending rings.
Figure 20 ONS 15327 with Multiple Subtending Rings
Figure 21 shows a path protection subtending from a BLSR. In this example, Node 3 is the only node serving both the BLSR and path protection. Optical cards in Slots 1 and 2 serve the BLSR, and optical cards in Slots 3 and 4 serve the path protection.
Figure 21 Path Protection Subtending From a BLSR
Linear Add/Drop Multiplexer Mode
In ADM configuration, intermediate nodes have direct access to eastbound or westbound STS channels along a fiber route, and can connect any STS to any other STS for transport along the network. ADM configurations eliminate the need for costly "back-to-back" terminal configurations and can be enhanced with 1+1 protection for any or all transport spans in the system. Figure 22 shows an ADM configuration.
Figure 22 Linear ADM Configuration
The ONS 15327 supports a full range of line rates as well as TDM and Ethernet/IP access tributary interfaces at every node in ADM configuration. The cross-connect helps to maximize bandwidth allocation by making it possible to map any tributary STS channel to any eastbound or westbound SONET span or to any other access tributary interface.
In terminal point-to-point configuration, one node is physically connected to another node with no intermediate nodes. The add-drop multiplexing feature is usually provided but not used in this configuration.
Figure 23 A Linear or Path Protection Connection Between ONS 15327 and ONS 15454 Nodes
Path-Protected Mesh Network
ONS 15327 networks give you the option of setting up PPMN. PPMN extends the protection scheme of path protection from the basic ring configuration to the meshed architecture of several interconnecting rings. Typical path protection protection creates two separate routes between source and destination nodes on a single path protection. PPMN does this for source and destination nodes that do not lie on the same ring but link together through a network of meshed connections. When applied to a single ring, PPMN uses the same paths as the path protection.
PPMN connects the source and destination of a circuit over two diverse paths through a network of single or multiple meshed rings. These two routes form a circuit-level path protection. The source sends traffic on each of the diverse routes to the destination node, where the destination node uses the active route or switches to the standby route. CTC can automatically route circuits across the PPMN, or you can manually route circuits.
Figure 24 shows an example of a PPMN. In the example, Node 3 is the source and Node 9 is the destination. Automated provisioning automatically determines that the shortest route between the two end nodes passes through Node 8 and Node 7, shown by the dotted line. Cross-connections are automatically created at nodes 3, 8, 7, and 9 to provide a working-traffic route.
If you check the protected circuit box in CTC, PPMN establishes a second unique route between Nodes 3 and 9 and automatically creates cross-connections at nodes 3, 2, 1, 11, and 9, shown by the dashed line. If a signal failure occurs on the primary path, traffic switches to the second, protected circuit path. In this example, Node 9 switches from the traffic coming in from Node 7 to the traffic coming in from Node 11 and service resumes. The switch occurs within 50 milliseconds.
Figure 24 Path-Protected Mesh Network With ONS 15327s and ONS 15454s
ONS 15327 and ONS 15454 Mixed Configurations
The ONS 15327 can mix BLSR, path protection, and PPMN configurations in any combination and with ONS 15454s. For example, a BLSR-configured ONS 15327 node can be linked to an ONS 15454 path protection.
Figure 25 shows an ONS 15327 subtended from an ONS 15454 path protection or BLSR.
Figure 25 ONS 15327s and ONS 15454s in a Mixed Configuration
The ONS 15327 supports up to twenty concurrent TL1 sessions that provide the full range of TL1 commands for provisioning and managing ONS 15327 nodes. The Cisco ONS 15454 and Cisco ONS 15327 TL1 Command Guide provides a complete list of commands, including specific sections devoted to ring provisioning and alarms and errors.
You can enable TL1 in three ways:
•Launch CTC and open a TL1 session to enter TL1 commands.
•Use port number 2361, 3082, or 3083 to access TL1 commands using a telnet session.
•Use the nine-pin RS-232 port on the XTC to open a VT100 emulation window and enter TL1 commands.
TL1 Gateway and TL1 Test Access
TL1 Gateway enables you to issue TL1 commands to multiple nodes using a single connection. This means you can now provision other nodes in the network from the workstation where you are logged in.
TL1 Test Access enables you to monitor and test circuits. Commands to connect, disconnect, and change the test access (TACC) connections are available.
RJ-45 LAN Connection
The XTC has two built-in interface ports for accessing the ONS 15327. With one RJ-45 interface browser LAN connection you can access the system using a standard browser interface. From the browser interface, you open a VT100 emulation window to enter TL1 commands.
Use port number 2361 to access the ONS 15327 TL1 commands using a Telnet session over a craft interface or RJ-45 LAN connection. The LAN connection is located on the front panel of the XTC card.
You can mount the ONS 15327 in a 19- or 23-inch, EIA or Telcordia-standard rack and up to 12 ONS 15327s can be used in a single 7-foot rack.You can access the ONS 15327 cards, cables, connectors, power feeds, and fan-tray assembly through the front of the ONS 15327 only.
The fan tray assembly is a removable drawer that holds fans and fan-control circuitry for the ONS 15327. After you install the fan tray, you do not need to remove it unless a fan failure occurs. The fan tray assembly has an air filter on the right side of the fan tray that you can install and remove by hand to visually inspect.
Figure 26 ONS 15327 Fan-Tray Assembly
You can use fiber-optic, coaxial, Champ, and twisted-pair cables to connect to the ONS 15327.
The ONS 15327 uses locking cable guides on each side of the shelf assembly to provide efficient cable management and to economize shelf space. The cable guides ensure that the proper bend radius is maintained in the fibers and that all other cables are properly routed. You can easily remove the fiber guides if necessary to create a larger opening, for example, if you need to route copper Ethernet cables out the side.
Figure 27 shows the cable guides routing cables from the front to the sides of the shelf.
Figure 27 ONS 15327 With Locking Cable Guides
–Height: 5.1 inches (13 cm)
–Width: 19 or 23 inches (48.3 or 58.4 cm) with mounting ears attached
–Depth: 11 inches (28 cm)
–Weight: 15 lbs, empty; 27 lbs, maximum
•Cisco Transport Controller
–XTC access: RJ-45 connector
–Database Storage: Nonvolatile 96 MB, FLASH memory
–2 DS-1 BITS inputs
–2 derived DS-1 outputs
–Internal Stratum 3 per Telcordia GR-253-CORE
–Free running accuracy: ± 4.6 ppm
–Holdover Stability: 3.7 x10 -7 /day, including temperature (< 255slips in first 24 hours)
–Reference: External BITS, line, internal
•TL1 Craft Interface
–Speed: 9600 baud
–Front panel access: RS-232 DB9 type connector
•External LAN Interface: 10 Base-T Ethernet
–Visual: Critical, Major, Minor, Remote
–Audible: Critical, Major, Minor, Remote
–Alarm contacts: 0.045mm, -48V, 50 mA
–Operating Temperature: 0 to +55 degrees Celsius (standard)
–Operating Temperature: -40to +65 degrees Celsius (I-Temp)
–Operating Humidity: 5 - 95% non-condensing
Input power: -48 VDC
–Power consumption: 260 W (maximum draw with cards)
–Power requirements: -42 to -57 VDC
–Power terminals: Spring Terminal block (#12 AWG)
–OC3 IR 4 1310
–OC12 IR 1310
–OC12 LR 1550
–OC48 IR 1310
–OC48 LR 1550
•Card Slot Assignment
–Total card slots: 8
–Traffic slots (Ethernet, Gigabit Ethernet, OC-3, OC-12, and OC-48): Slots 1- 4
–XTC (Cross-Connect, Timing, and Control): Slots 5, 6
–MIC (Mechanical Interface Card): Slots 7, 8
–Add-drop multiplexer (ADM)
–Two-fiber bidirectional line switched ring (BLSR)
–Two-fiber path protection
–Path-protected mesh network (PPMN)