VRC Version 1.1 is targeted for H.323-based networks. H.323 VoIP dial plans are statically configured and managed on gateway and gatekeeper platforms. The infrastructure of a typical H.323 VoIP network includes gateways and gatekeepers.
In a typical service provider network, a number of gateways are deployed at points of presence (POPs) throughout the service provider coverage area. A gatekeeper is used to group these gateways into a logical zone of control and perform all call routing among them.
To simplify dial plan administration for these multiple gatekeeper networks, Cisco introduced the concept of a directory gatekeeper to handle call routing between local gatekeepers.
VRC is a software product that runs on Sun servers and provides a GUI client running within a browser on PCs running the Windows operating system.
VRC software can be used:
As a standalone application
Integrated with Packet Telephony Center (PTC)
You can deploy VRC to discover the dial plan of an existing network. You can also use it to design new dial plans incorporating Cisco routers running as gateways, gatekeepers, and directory gatekeepers.
The VRC is designed to administer a VoIP network at two levels:
Administrative Domain (AD)—The highest level of administration which encompasses the entire dial plan. The AD includes all elements that participate in the VoIP call routing.
Regions—A region partitions the AD. It may contain one or more zones, gatekeeper groups, and directory gatekeepers.
VRC Version 1.1 uses CNS security services for user administration and authorization.
The VRC application is a tool for dial plan provisioning including:
Discovering existing dial plan configurations
Designing new dial plan configurations
Validating new dial plan configurations
Previewing new configurations
Distributing new configurations to network elements
Archiving existing dial plans with the ability of restoring an earlier configuration
The VRC application consists of a centralized dial plan management server and web-based clients distributed across an IP network. The server uses a database for storing configuration information and is responsible for all direct interaction with each managed network element. These communications occur using the Cisco IE2100 or over Telnet and HTTP protocols.
When you use VRC integrated with PTC:
VRC is launched from the PTC user interface.
Network operations are managed through the PTC Topology Manager. These include adding and deleting regions and network elements from the topology. The VRC view is not accessible from the VRC client.
When you make changes to a dial plan and commit the design, any topology update, such as adding a gateway to a zone, is automatically reflected in the PTC Topology Manager.
When you change network elements through PTC, these changes are sent to VRC as events and the elements affected by the change are flagged in the VRC Baseline View and Design View.
The VRC is a web-based client/server architecture. The server resides on a Sun platform. It uses MySQL for its database needs and Tomcat for a servlet engine. For user management it uses the Cisco CNS Security module which has an embedded LDAP directory from DCL. The VRC code is implemented in Java and uses the Java 1.3 run-time environment. The client is a Java applet that runs within a standard Internet Explorer Version 5.0 or Version 5.5 web browser.
Note When VRC is integrated with PTC, PTC manages VRC installation, CNS security installation, and
topology operations.
VRC provides basic provisioning of dial plans and configuration of the elements in a network and with the VRC. You can also archive and restore dial plans and validate the configuration before downloading it to the elements. The VRC can be deployed in a network with an existing dial plan or it can be used to create new dial plans.
VRC uses the Cisco IOS version to determine what command line interface (CLI) it needs to generate to configure a network element. VRC applies the term "feature set" to capture the dial plan capabilities of a Cisco IOS version.
The VRC Version 1.1 model supports the following feature sets:
dp1.0—Supports prefix routing.
dp1.1—Supports both prefix routing and carrier-sensitive routing. Devices that support dp1.1 support gateway and gatekeeper trunk and carrier-based routing enhancements.
The feature set for the device depends on the Cisco IOS version running on the device.
*Denotes all releases of this Cisco IOS version. For example, Release 12.2(2)XB* means that the network element supports the following Cisco IOS versions: Release 12.2(2)XB1, Release 12.2(2)XB2, Release 12.2(2)XB3, Release 12.2(2)XB4, and all releases following.
Most VRC operations can occur simultaneously by different users within the VRC server. However, there are certain operations that cannot run concurrently.
VRC concurrent operations constraints include:
A single user can execute only one operation at a time.
There can only be one design session open at a time for a given scope.
Design sessions that originate with the Discovery operation are opened at the AD level.
Table 1-2 lists the VRC operations that cannot occur simultaneously.
View generated CLI (both baseline and design views)
Import Topology
Element activation or reactivation
Check network element
Persist element configuration
View generated CLI (baseline view)
Export baseline dial plan
Because the following operations require serialized access to staging tables, they are semi-concurrent with the Commit operation:
Design Preview
View the generated CLI (both the Baseline View and Design View)
If you receive an error message that an operation cannot be executed because it cannot be initialized, wait a few moments and try again. VRC might be waiting for an operation to complete, or that operation must be in the initialized state before you can execute another operation.
Note If you are using a Cisco IE2100 device for automating the deployment and management of network
devices, your concurrent operation issues might be different.
Administrative Domain (AD)—The entire VoIP network whose dial plan is managed by VRC.
Address resolution authority (ARA)—The network element assigned to a zone to provide address resolution service to all the elements of the zone. An example of an ARA could be a gatekeeper group or OSP server.
Baseline dial plan—The fully committed version of the dial plan. At any given time, there is only one baseline version of the dial plan for the entire AD. This represents the actual configuration of the network.
Design session—A transactional mode of operation through which a user may make changes to the baseline.
Dial plan—A numbering plan for the voice-enabled network.
Directory gatekeeper (DGK)—An H.323 gatekeeper that provides address translation support only for other gatekeepers and not for gateways.
Directory gatekeeper group (DGKGrp)—A set of directory gatekeepers that you configure for redundancy.
Discovery—The operation by which VRC queries network elements for their current dial plan related configuration and updates the baseline to match.
Distribution—The process by which VRC distributes the dial plan to network elements such that their configuration matches the baseline.
Element—A router with physical counterparts used in the dial plan.
Gatekeeper (GK)—An H.323 entity on a LAN that provides address translation and control access for H.323 terminals and gateways.
Gatekeeper group (GKGrp)—A dial plan component composed of one or more physical gatekeepers.
Gateway (GW)—A network access server (NAS) that acts as an interface between a circuit-switched Public Switched Telephone Network (PSTN) and a packet H.323 Voice-over-IP (VoIP) network.
Region—Logical set of zones that partition the VoIP administrative domain. The two types of regions are managed and foreign.
Routes—Represent calls that leave (egress) or enter (ingress) a zone in the VoIP network.
Scope—A logical area (an entire AD or a region) managed by the network administrator and used to organize the network using the VRC application.
Views—VRC has three distinct modes of operation, called views. Each view provides different capabilities for managing a dial plan.
Topology—Identifies the set of elements that can participate in a dial plan. Identifies the partitioning of those elements into regions which can be independently managed. When integrated with PTC, VRC uses the PTC Topology Manager.
Baseline—Represents the current dial plan. The baseline is consistent with the physical network but can differ if dial plan changes are made outside of VRC. Committing a Discovery causes the baseline to be updated to reflect the dial plan on the physical network.
Design—Used to make changes to an existing dial plan. Includes introducing network elements with no previous dial plan configurations into a dial plan design. To update the baseline dial plan and configurations for the added elements, you must commit the dial plan design. You can also start a new dial plan design session in the Design View.
