Route Lists and Route Groups The information in this presentation is directly quoted from the Cisco CallManager Fundamentals book. Many thanks for the authors and for the Prentice Hall publishing company for allowing me to use the book (information, diagrams, topologies, and tables) in my presentation.
Why? • When your network grows beyond the capacity of a single gateway, you are posed with a problem: how do you configure CM so external calls can use both gateways, and how can you make CM choose the correct gateway when only one gateway has trunks available? • Route lists and route groups are the answer.
Route List and Route Group Operation • A route group represents a list of several individual gateways. • When a route group receives a call, it offers the call to the first device in its list. If the device can accept the call, the route group’s job is done. If, however, the device rejects the call because it is being fully utilized or it is out of service, the route group then offers the call to the next device in its list. Only when all devices have rejected the call does the route group reject the call. • A route list is an ordered list of route groups • Where a route group sequentially offers calls to devices in its list, a route list sequentially offers calls to route groups in its list. A route list rejects an outgoing call only when no route groups in its list can accept the call.
Route Lists and Transformations • Route lists provide you with additional routing control • The calling and called party transformations on route lists allow you to override, on a route-by-route basis, the calling and called party transformations that you assigned to the route pattern that selected the route list. • You may need to override transformations on a particular route basis to properly format a number for the gateway that receives a call. • Transformation rules on a route overrides transformation rules on a route pattern • The term “Route” refers to the association between a route list and one of its route groups
Case-Continued • Company XYZ with two locations: Dallas and San Jose • Two equivalent gateways in San Jose and one gateway in Dallas • Route Groups: • SanJoseRoutGroup: • MGCP Gateway in SJ (VGW1) • H.323 Gateway in SJ (VGW2) • DallasRouteGroup: • Voice gateway in Dallas (VGW3) • Route List (Toll Restriction): • SanJoseRouteGroup • DallasRouteGroup: • Route Pattern: 9.@ • Route Filter: Area-Code ==408 • Dialing Transformations on the route: • Convert the 12 digit number that the user dials from Dallas to a 7-digit number for routing on the San Jose PSTN • Example: Convert: 9 1 408 555 1212 to 555 1212
Case-Continued When a user in Dallas dials 9 1 408 555 1212 the route list performs the following steps: • First, it attempts to offer the call to the first gateway listed I the San Jose gateways route group. This gateway is an MGCP gateway connected to the San Jose PSTN. Because CM manages the state of the trunk interfaces of MGCP gateways. The gateway component can immediately reject the call attempt. • Second, it attempts to offer the call to the second gateway listed in the SJ gateway route group. This gateway is an H.323 gateway, which manages the state of its own trunk interface. CM offers the call to the gateway, but the gateway rejects the call. • The SJ route group rejects the call that the DallasToSanJose route list extended, so the DallasToSanJose attempts to route the call over the PSTN. It extends the call to the Dallas gateways route group. The transformation that the route pattern applied to the called number to convert it to 555 1212, however, would prevent the call from routing from Dallas, so dialing transformation on the route list override the called party transformation the route pattern applied, the route converts the number to 1 408 555 1212 and then offers the call to the Dallas gateway.
Assigning Gateways to Route Groups and Route Groups to Route Lists • In which order should you build your route list structure??? • First you start by configuring gateways, which you then place into route groups. Once the route groups are organized, you place them in route lists. Finally, you control routing to these route lists by assigning route patterns.
Creating Gateways • Types of gateways: • MGCP • H.323 • SIP
Assigning Gateways to Route Groups • Each gateway endpoint a CallManager route to can exist in , at most, one route group. • An Endpoint differs based on the type of gateway (device Vs interface) • Only gateways that are equivalent for routing purposes can be in the same route groups • Example: VGW1 and VGW3 even though they nominally provide access to the same place, they can not be in the same route group because they are not equivalent for routing purposes: Calls from Dallas to SJ through VGW3 requires 11-digit dialing while calls through VGW1 don’t. (same applies for VGW2 and VGW3) • A route group can list its gateways in only one order.
Assigning Route Groups to Route Lists • Route Lists are ordered lists of route groups. • Although a given gateway end point can exist in at most one route group, a route group can exist in any number of route lists. • A route list is simply a gateway search pattern. Generally, for every unique order in which you wish to attempt to route calls to gateways, you need one route list. • The purpose of a route list is wholly determined by the route pattern you assign to it and the route groups it contains.
How Calling and Called Party Transformations Work • Each route contain the same calling an called party transformation that exist on the route pattern itself. • The calling party transformations are : • The Prefix Digits • Calling Party Transformation Mask • And the “Use External Phone Number Mask” • The called party transformations are: • Digit Discarding Instructions • Called Party Transformation Mask • And Prefix Digits • When you add a Route Group from the Route List Configuration screen, CM Administration opens the Route Details Configuration screen, where you can customize the dialing transformation that CM applies when it offers a call to the selected route group from the current route list.
Route Lists and Route Groups and Toll Bypass • A toll bypass configuration requires the dial plan to be able to distinguish types of outside calling. For instance, emergency calls must route out only those gateways local to the calling user. Local calls should preferentially rout out gateways local to the calling user. On the other hand, calls to other LATAs where you manage gateways need to route preferentially to those remote gateways. Finally, long distance and international calls can route out any gateway in the network . The need to distinguish between types of PSTN calls requires the use of route filters.
Route Lists and Route Groups and Toll Bypass • When a user dials along distance number that routes to a remote gateway, usually the number the user dial is not a valid number when dialed from the remote gateway itself. From the user’s point of view, the number is a long distance number, so CM should accommodate a long distance numbering format. For instance, North American users typ9cally dial 11 digits when dialing another geographic region, But the same destination as dialed by a user in the remote location is either seen or ten digits. Allowing the call to route properly once it reaches a remote location requires using called party transformations.
Route Lists and Route Groups and Toll Bypass • Calling number is also an issue when a call crosses LATA boundaries. If a user in Boston places a toll bypass call through a gateway in Orlando, how should CM represent the calling number? If it presents A Boston calling number, the Orlando central office may complain, because it dons no t recognize the number of the caller. It is often necessary either to transform the calling number to an attendant number in the remote location or to alias the calling number to a number that is valid in the remote location, these modifications require the use of calling party transformations.
Route Lists and Route Groups and Toll Bypass • If locations contain more than one gateway, route lists provide a way to maximize gateway usage. • Users in different locations need to reach different location, even if they dial the same digit strings. For instance, a user in Dallas who dials 911 needs to reach Dallas emergency services, while a Boston user needs to reach Boston emergency services. Giving different users different views of the same network requires the use of calling search spaces and partitions.
Example Company ABC – Two Locations – Three levels of PSTN Access
SJ Location 30000 is the attendant. The gateway is connected to the 555 exchange in the 408 area code. The PSTN has assigned a range of 5000-5999 to the San Jose site. For the purpose of this example, users in SJ dial seven digits to make local calls.
Dallas Location 40000 is the attendant. The gateway is connected to the 555 exchange in the 972 area code. The PSTN has assigned a range of 2000-2999 to the Dallas site. For the purpose of this example, users in Dallas dial seven digits to make local calls.
Building a Toll bypass configuration • Building a toll bypass configuration occurs in two phases: • Outbound Dialing: Which includes: • Building route groups and route lists for external access, • Creating route filters for different levels of user access, and routing by geographical region, • Transforming the calling and called parties, • And assigning calling search spaces. • Inbound Dialing: which includes: • Building translation patterns to map external phone number sot internal extensions, • Assigning Calling Search Spaces to control the destination inbound gateway calls can reach
Outbound Dialing: Route Group and Route List Creation • Defining the route group: • Assign the SJ gateway to route group SanJoseGateways and Dallas gateway to route group DallasGateways. • Before defining the route lists you must understand the concept of fallback: • Fallback is the process of offering a call to a lass desirable gateway after all desirable gateways have been exhausted.
Outbound Dialing: Route Filter Creation and Route Pattern Assignment In All cases the route pattern is: 9.@
Outbound Dialing: Partitions The enterprise rules define two locations and three levels of outside calling. This argues for six different partitions for outside dialing plus a partition for company ABC for inside dialing.
Outbound Dialing: Applying Calling and Called Party Transformations
Outbound Dialing: Applying Calling and Called Party Transformations
Outbound Dialing: Calling Search Space Assignment Create the calling search spaces and assign them to calling devices
Inbound Dialing-Defining Translation Patterns Although this example permits the use of gateway called party transformations to convert an inbound phone number to an extension number, configuring the map using translation patterns saves some reconfiguration effort if you ever purchase another phone number range from the phone company. San Jose gateways and Dallas gateways need individualized translation patterns.