Cisco® Packet Telephony Center Virtual Switch (PTC VS) provides the carrier-class network management functions, scalability, and reliability required by telephony centers and telecommunications service providers. Cisco PTC VS features include virtual entity and management concepts, multiuser support, multithreaded programming, and Web-browser-based client access. Please refer to Table 1 for a summary of PTC VS features and benefits and the PTC VS white paper for detailed information.
Cisco PTC VS is a carrier-class service and network management system that provisions a voice-over-IP (VoIP) tandem softswitch, the virtual packet-voice-switch connection between the Public Switched Telephone Network (PSTN) and the VoIP service provider networks H.323 dial plan. As the voice domain manager, Cisco PTC VS provides the foundation for fault, configuration, accounting, performance, and security (FCAPS) management capability, enabling service providers to deliver a comprehensive end-to-end management solution.
Cisco PTC VS enables rapid adoption of new packet voice network technology by providing network management tools comparable to those in the PSTN environment. This helps to simplify network management and enables integration of the new VoIP network for coexistence with the legacy PSTN. Service providers are able to reduce costs by using the more efficient packet network and taking advantage of its value-added services.
Cisco PTC VS offers virtual entity management for the packet voice network similar to that of the traditional time-division multiplexing (TDM) networks (to achieve logical functioning and usability equivalent). Cisco PTC VS version 3.0 adds support for Media Gateway Control Protocol (MGCP) and for many new network devices.
Example of Cisco PTC VS Managing an H.323 VoIP Network
Table 1 Features and Benefits of Cisco PTC VS
Many packet voice network service providers have concerns regarding network and system management requirements, network provisioning procedures, and service activation requirements because of the complexities inherent in VoIP network architectures. Traditional TDM networks involve monolithic network elements that hide much of their internal complexity. Some of this complexity is now exposed in the packet switch network because the same functions are distributed over several independent and cooperating components (Figure 2). Each network element or component on its own is significantly lower in cost and simpler than a TDM switch, but this simplicity is exchanged for higher complexity of the network as a whole, which now contains a greater number and variety of components. Consistent provisioningof control connectivity as well as provided servicescan be a challenge because multiple network elements need to be configured in unison in order to provide voice services. Cisco PTC VS tackles this network management consistency challenge with virtual entity constructs to offer simplicity and unanimity for network management in the packet voice network.
TDM and Packet Switch Comparison
Cisco PTC VS is a carrier-class (VoIP) domain manager featuring comprehensive network management and end-to-end service-level provisioning, as well as interfaces for supporting OSS integration. Cisco PTC VS consolidates and simplifies VoIP network management tasks by offering a consistent network service provisioning model. Cisco PTC VS is a potent management solution that provides holistic management of voice networks using virtual entity concepts (Figure 3), including:
- A virtual SS7 gateway that deals with dependencies between an H.323 gateway and a signaling controller in which SS7 traffic is converted to Q.931 signaling protocol for the gateway
- A virtual zone that deals with dependencies between gateways within a zone as well as between gateways and gatekeepers
- A zone connection that deals with dependencies between gatekeepers, or between gatekeepers and directory gatekeepers
How Cisco PTC VS Manages Virtual Entities
A high degree of scalabilitymade possible through the use of the Cisco Series Intelligence Engine CNS 2100 configuration applianceenables the product to facilitate network growth and expansion. The browser console of Cisco PTC VS provides a centralized GUI that supports simultaneous multiuser access. The GUI serves as the single data entry point for all network provisioning and service configuration tasks.
In addition to providing support for virtual entities requiring consistent configuration of multiple network devices, Cisco PTC VS supports configuration operations for an entire region or zone, giving users a means of performing high-density and bulk-provisioning tasks. For example, this feature enables an operator to apply a given gateway configuration to all gateways for a zone or region. In fact, many Cisco PTC VS provisioning operations lead to multiple management requests issued to various managers and network elements behind the scenes to provide simplified, holistic virtual entity operation.
The wizard-driven screens of Cisco PTC VS provide default configuration and provisioning profiles to help network operators navigate the basic and advanced input screens needed to manage the packet voice network (Figure 4). Cisco PTC VS also offers the network operator dynamic "mouse-over" pop-up help windows.
Cisco PTC VS Provisioning GUI
In addition to provisioning and topology, Cisco PTC VS version 3.0 adds the ability to manage voice routing dial plans for gateways, gatekeepers, and directory gatekeepers in the H.323 network. Cisco PTC VS enables administrators to design, configure, deploy, and manage dial plans in Cisco H.323 VoIP networks. Through its graphical user interface (GUI), Cisco PTC VS centralizes and coordinates call routing configurations for thousands of VoIP gateways and gatekeepers within a single application. A good dial plan makes optimal use of network resources, ensures that all calls are routed appropriately, implements business rules for routing efficiencies, and minimizes PSTN toll charges. The dial plan can be the most complex part of the VoIP network to configure. Cisco PTC VS accomplishes these dial-plan objectives via a wizard-driven user interface, reducing the complexity and simplifying the task of managing, adding, deleting, and modifying the dial plan.
Cisco PTC VS provides automated discovery of network element configuration and a graphical network management topology view as well as topology synchronization. It also detects and avoids network configuration problems.
Figure 5 shows a Cisco PTC VS topology view. The left pane shows the components of the virtual entities and of the network using a file explorer metaphor. The physical network topology of these components is pictured in the right pane. The Cisco PTC VS topology view presents physical entities in the network in virtual and physical views, enabling network operators to easily navigate and manage across the distributed VoIP network.
Cisco PTC VS Virtual Network View
Cisco PTC VS provides comprehensive VoIP network management capabilities. It not only supports provisioning (the generation and delivery configurations to multiple devices), but also supports configuration retrieval to provide an accurate image of the actual network configuration. By validating the current configuration of individual components against the expected virtual entities, network operators can be alerted to violations of integrity rules that might be introduced if operating personnel "work around" the Cisco PTC VS by configuring network devices directly using the command-line interface (CLI). Operators can also identify violations that were introduced before Cisco PTC VS was installed.
Without Cisco PTC VS, configuration inconsistencies of this nature can be difficult to detect and can lie undetected in the network, invisible in an EMS view. A gateway and a signaling controller should be configured to point toward each other. In Figure 6, the gateway (b) should point to the signaling controller (a) and the signaling controller (a) should point back to (b). However, because of an erroneous configuration performed manually at the devices, the signaling controller points to a different gateway (c). While the configuration of each network element in isolation is perfectly legal, network level configuration integrity is violated, resulting in dysfunctional service at both gateways.
Detecting Inconsistent Virtual Gateways
Table 2 Network Elements Supported by Cisco Packet Telephony Center
|PTC VS 3.0 Supported Platforms (updated, 04/02/03)|
|IOS Devices Supported|
|Device Name||Supported Release|
|Non IOS Devices and EMSs Supported|
|Device or EMS Name||Supported Release|
In response to the critical need for an effective, comprehensive VoIP network management tool, Cisco has delivered Cisco PTC VS, engineered to provide vital functions for overall VoIP network management and service provisioning. Its multiaccess Web GUI empowers customers with a central entry point for complete network administration. Cisco PTC VS can detect all physical network elements and create the virtual network entities or objects that are part of the voice service network. Detailed information about these elements is retained in an object model and is dynamically updated as events occur in the network, allowing Cisco PTC VS to maintain synchronization and accurately reflect the network topology. The object model is critical to the creation and intelligent management of the virtual objects.
Cisco PTC VS is designed with carrier-grade scalability, making it suitable for deployment in small-, medium-, or large-scale VoIP networks. Because VoIP technology deployments are increasing, Cisco PTC VS is the perfect tool to significantly reduce the complexity involved in managing these packet voice networks, allowing technicians and engineers responsible for network management to perform simplified end-to-end provisioning tasks. Cisco PTC VS's open interface architecture offers access to customers' existing OSSs and eases efforts for third-party integration, as well.
Cisco PTC VS helps service providers realize considerably reduced network operations and management costs, reduced time to market for new customers and services, and reduced time to revenue, resulting in greater customer stability. Cisco PTC VS contributes to increased revenue and a reduction in the service provider's total cost of network ownership.