Route Lists and Route Groups

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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.
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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.

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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 groups 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.

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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

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Route Lists and Route Groups-Case
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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._at_
• 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

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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.

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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.

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Creating Gateways

• Types of gateways
• MGCP
• H.323
• SIP

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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 dont. (same
  applies for VGW2 and VGW3)
• A route group can list its gateways in only one
  order.

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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.

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Assigning Route Groups to Route Lists
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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.

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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.

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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 users
  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.

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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.

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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.

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Example
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Example
Company ABC Two Locations Three levels of
PSTN Access
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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.
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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.
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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

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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.

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Outbound Dialing Route Group and Route List
Creation
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Outbound Dialing Route Group and Route List
Creation
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Outbound Dialing Route Filter Creation and
Route Pattern Assignment
In All cases the route pattern is 9._at_
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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.
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Outbound Dialing Assigning Route Pattern and
Filter to Route Lists
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Outbound Dialing Applying Calling and Called
Party Transformations
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Outbound Dialing Applying Calling and Called
Party Transformations
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Outbound Dialing Calling Search Space Assignment
Create the calling search spaces and assign them
to calling devices
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Outbound Dialing Calling Search Space Assignment
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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.
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Inbound Calling Search Spaces