Designing Dial Plan Single Cisco UCM Cluster
Dial Plan Design With a distributed Cisco UCM Cluster and Cisco CMS Cluster in Multisite Architecture.
The deployment consists of one Cisco UCM Cluster and one Cisco CMS Cluster distributed accross three sites, US, UK and GE. In this type of deployment, there are some recommendations that should be taken into considerations
The first recommendation is to reduces the number of distribution links required to connect the participants in the conference, and therefore reduces the load across the CMS node and distributed calls accross the WAN. To achieve this requirement, we use the CallBridge Group feature. We create Three CallBridge Groups for each site, and we associate the local to each CallBridge Group.
The second recommendation is to optimize the outgoing calls from the Cisco UCM Cluster.
A SIP Trunk must be configured to each CallBridge.
Three Route Groups for each site must be created to group the SIP Trunk to the remote CallBridges located in each site. For example the Route Group RG-UK will group the CallBridges of the Site United Kingdom UK (UK-CMS1 and UK-CMS2).
Three Device Pools and three UCM Groups must be created for each site.
Each UCM Group must be associated to the corresponding Device Pool, for example, the UCM Group RG-UK will be associated to the Device Pool DP-UK.
Each endpoint will use the Device Pool to register to the local Call Controls.
All CallBridges share the same space and a single Route Pattern must be created with a single Route List. The Calls received by the Call Control must be routed to the local CallBridges. To achieve this, we need to use the Local Route Group with a single Route Pattern and Route List. The decision to route the calls to the local CallBridges is done through the Device Pool where the Local Route Group for each site is associated.
For the CallBridge Group to work, There are two requirements:
The first requirement: We need to enable the "Accept Replaces Header" on all SIP Trunk so that the call control is able to move SIP calls between Call Bridge Groups as instructed by the CallBridges when sending the SIP INVITE with Replaces Header.
The second requirement: we need to assign the appropriate Rerouting CSS on all SIP Trunk, this Rerouting CSS must include the Line Partition of the endpoint so that the Call Control is able to send a SIP UPDATE to the endpoint when moving the call to another CallBridge hosting the meeting.
Finally to optimize the outgoing calls from the Call Controls's perspective, we need to enable the "Run On All Active Unified CM Nodes" option on the Route List and the SIP Trunks, this option ensures that the Call Control where the endpoint is registered to is always used to route the egress calls.
Designing Dial Plan with Separate CUCM Cluster and Single CMS Cluster
In this scenario, there are two separate CUCM clusters.
- The first cluster is located in HQ-site with HQ-CUCM and HQ-CUP.
- The second cluster is located in BB-site with BB-CUCM and BB-CUP.
A Cluster of two Cisco Meeting Servers are distributed accross sites. HQ-CMS is deployed in HQ-Site while BB-CMS is deployed in BB-Site.
Both CMS are clustered and share the same space with the User Part URI 882222.
To optimise intersite bandwidth usage, the local CUCM should send calls to join meeting from local users to local Cisco Meeting Server, if the local CMS is not available, the remote Cisco CMS can be used as a backup.
To optimize load balancing with failover, if the local CMS is not available, a prefix « 8 » must be added when a user dial 882222 by the local CUCM and the called number 8-882222 will be presented to the remote CUCM.
The remote CUCM must have a route pattern 8.88XXXX to route the call to remote CMS. The prefix « «8 » must be stripped before sending the call so that the call number 882222 will match the User Part URI of the space World Cup Espana 1982.
SIP Trunks are configured as follow:
- HQ-CUCM and BB-CUCM are configured with a SIP Trunk.
- HQ-CUCM is configured with SIP Trunk to HQ-CMS.
- BB-CUCM is configured with SIP Trunk to BB-CMS.
To design our dial plan.
On each CUCM, we need two Route Groups.
On HQ-CUCM.
- The Route Group named RG-HQ-CMS-LOCAL contains SIP Trunk to HQ-CMS.
- The Route Group named RG-BB-CMS-REMOTE contains SIP Trunk to BB-CUCM.
On BB-CUCM.
- The Route Group named RG-BB-CMS-LOCAL contains SIP Trunk to BB-CMS.
- The Route Group named RG-HQ-CMS-REMOTE contains SIP Trunk to HQ-CUCM.
Now we need two Route Lists on each CUCM.
On HQ-CUCM.
- The first Route List is named RL-HQ-CMS-Failover, it contains the Route Groups RG-HQ-CMS-LOCAL placed first in the list and RG-BB-CMS-RMOTE.
- The second Route List is named RL-HQ-CMS and it contains the Route Group RG-HQ-CMS-LOCAL.
On BB-CUCM.
- The first Route List is named RL-BB-CMS-Failover, it contains the Route Groups RG-BB-CMS-LOCAL placed first in the list and RG-HQ-CMS-RMOTE.
- The second Route List is named RL-BB-CMS and it contains the Route Group RG-BB-CMS-LOCAL.
Finally, we configure two Route Patterns on each CUCM.
On HQ-CUCM.
- Route Pattern 882XXX that points to to the Route List RL-HQ-CMS-Failover.
- Route Pattern 8.882XXX that points to to the Route List RL-HQ-CMS.
On BB-CUCM.
- Route Pattern 882XXX that points to to the Route List RL-BB-CMS-Failover.
- Route Pattern 8.882XXX that points to to the Route List RL-BB-CMS.
To connect successfully jabber client to the remote CMS in the event that the local CMS is not available we need to perform two digits manipulation of the dialed number 882222.
The first digits manipulation is to add prefix « 8 » to the called number 882222 when the call from Zico user located at the HQ-Site is sent to the remote CMS BB-CMS through the SIP Trunk to BB-CUCM. This transformation is done at the Route Group RG-BB-CMS-RMOTE in the Route List Details RL-HQ-CMS-Failover.
For Zoff user located at the BB-Site, the same logic is applied. When the call is sent to the remote CMS HQ-CMS through the SIP Trunk to HQ-CUCM. This transformation is done at the Route Group RG-HQ-CMS-RMOTE in the Route List Details RL-BB-CMS-Failover.
The second digits manipulation is to strip the prefix « 8 » when the call arrives at the remote CUCM.
For Zico user, once the call with called number 8-882222 arrives at BB-CUCM, the route pattern 8.882XXX wil route the call to BB-CMS, but before sending out the call, we need to strip the prefix « 8 » at the Route Pattern level 8.882XXX using the Discard Digits « PreDot ».
For Zoff user, the same logic is applied, once the call with called number 8-882222 arrives at HQ-CUCM, the route pattern 8.882XXX wil route the call to HQ-CMS, but before sending out the call, we need to strip the prefix « 8 » at the Route Pattern level 8.882XXX using the Discard Digits « PreDot ».
The Dial Plan should configured as follow :
On HQ-CUCM
On BB-CUCM
Designing Dial Plan With Cisco SME Session Management Edition for Conferencing
Three separate Clusters CUCM are deployed with Multisite Architecture in the US site, GE site and AU site.
A single Cluster Cisco Meeting Server is deployed and distributed accross the WAN. Each Site contains two Cisco Meetine Server nodes running the callbridge services.
The Cluster CUCM in each site is trunked to the local callbridges.
Each cluster CUCM IS trunked to the SME as leaf nodes.
Standard Local Route Group will be used to reduce the number of Route Pattern, Route List, CSS and Partitions. The SIP Trunk selection for outgoing calls is based on the Route Group at the device pool level.
In each site, the call control contains two Route Groups, the first Route Group contains the SIP Trunks to the local callbridges and the second Route Group contains the SIP Trunk to SME.
On US-CUCM :
On GE-CUCM :
On AU-CUCM :
On each CUCM cluster (US, GE, AU and SME), a single route pattern pointing to a Route List containing two Local Route Groups.
In this deployment, the design of Device Pool is very important to achieve the goal of Load Balancing and Failover.
Device Pools in this deployment have three goals.
The first goal. For each site, routing calls to the local callbridges, if the local resources are not available, call must be sent to the remote callbridges.
In this case, a device pool for each site’s phones must contains two Local Route Groups :
Local Route Group LRG-LOCAL populated with the Route Group (RG-US, RG-GE and RG-AU) that contains the corresponding local callbridges.
Local Route Group LRG-REMOTE populated with the Route Group RG-SME that contains the SIP Trunk to SME.
You must create a device pool for each site (DP-US, DP-GE and DP-AU) and assign it to the phone.
On US-CUCM :
On GE-CUCM :
On AU-CUCM :
The second goal is for processing incoming calls from each site to SME. The SME must be able to process inbound calls when a specific Call Control wants to failover to another site in case of unavailability of the local resources.
For example, for users on US Site, if the local callbridges US-CMS1 and US-CMS2 are not available, the SME must process the incoming calls from US-CUCM in order to connect the users at the US Site to the remote callbridges (either to GE callbridges or AU callbridges) so that they will be used as a backup.
The same logic is valid to incoming calls from GE-CUCM and AU-CUCM.
To achieve this second goal, three device pools should be created on SME, let’s say DP-US-SITE, DP-GE-SITE and DP-AU-SITE.
Each device pool should have the following settings for the Local Route Groups LRG-LOCAL and LRG-REMOTE :
- The Local Route Group LRG-LOCAL should be set to NONE.
- The Local Route Group LRG-REMOTE should be set to the Route Group that contains two SIP Trunks towards the two remotes sites.
For US Site, SME should be configured with :
1-Route Group RG-US-SITE that contains the SIP Trunks to GE-CUCM and AU-CUCM.
2-Device Pool DP-US-SITE with :
- LRG-LOCAL = NONE
- LRG-REMOTE = RG-US-SITE
For GE Site, SME should be configured with :
1-Route Group RG-GE-SITE that contains the SIP Trunks to US-CUCM and AU-CUCM.
2-Device Pool DP-GE-SITE with :
- LRG-LOCAL = NONE
- LRG-REMOTE = RG-GE-SITE
For AU Site, SME should be configured with :
1-Route Group RG-AU-SITE that contains the SIP Trunks to US-CUCM and GE-CUCM.
2-Device Pool DP-AU-SITE with :
- LRG-LOCAL = NONE
- LRG-REMOTE = RG-AU-SITE
To make the failover process fine, SME must be able to process incoming calls from US GE and AU sites so that US Calls will be sent to GE or AU callbridges (GE calls to US or AU callbridges, AU calls to US or GE callbridges), we need to associate the Device Pool to the appropriate SIP Trunk.
The implementation should be :
- SIP Trunk to US-CUCM must be in the device pool DP-US-SITE
- SIP Trunk to GE-CUCM must be in the device pool DP-GE-SITE
- SIP Trunk to AU-CUCM must be in the device pool DP-AU-SITE
The third goal is to process the incoming calls at the remote sites when SME sends out the inbound calls after failover.
On each call control (US-CUCM, GE-CUCM and AU-CUCM), we need a device pool for calls coming from SME.
- US-CUCM with device Pool DP-SME
- GE-CUCM with device Pool DP-SME
- AU-CUCM with device Pool DP-SME
Each remote site must select the local callbridge to connect the call. In order to achieve this goal. The Local Route Group settings on each device pool must be set as follow :
On US-CUCM :
1-Route Group RG-US that contains the SIP Trunks to local callbridges US-CMS1, US-CMS2.
2-Device Pool DP-SME with :
- LRG-LOCAL = RG-US
- LRG-REMOTE = NONE
On GE-CUCM :
1-Route Group RG-GE that contains the SIP Trunks to local callbridges GE-CMS1, GE-CMS2.
2-Device Pool DP-SME with :
- LRG-LOCAL = RG-GE
- LRG-REMOTE = NONE
On AU-CUCM :
1-Route Group RG-AU that contains the SIP Trunks to local callbridges AU-CMS1, AU-CMS2.
2-Device Pool DP-SME with :
- LRG-LOCAL = RG-AU
- LRG-REMOTE = NONE
Then assign the device pool to the SIP Trunk that receives the incoming calls from SME as follow :
On US-CUCM :
SIP Trunk to SME must be in the device pool DP-SME.
On GE-CUCM :
SIP Trunk to SME must be in the device pool DP-SME.
On AU-CUCM :
SIP Trunk to SME must be in the device pool DP-SME.
Below summary of the design.
Chart Call Flow
- Incoming call from a US endpoint to 882222 is recieved by on US-CUCM.
- US-CUCM matches this call against the Route Pattern 882XXX, resolves that to Route List RL-CMS and then to the Local Route Groups LRG-LOCAL and LRG-REMOTE.
- With Standard Local Route Group LRG-LOCAL, US-CUCM uses the device pool of the endpoint to find the route group RG-US.
- The Route Group RG-US contains two SIP Trunks to the local CallBridge US-CMS1 and US-CMS2.
- US-CUCM sends the call to US-CMS1 or US-CMS2.
- If all US CMS are unavailable, US-CUCM will route the call to another element in the Route List RL-CMS.
- US-CUCM select the second Standard Local Route Group LRG-REMOTE.
- US-CUCM uses the device pool of the endpoint to find the local route group RG-SME.
- The Route Group RG-SME contains only the SIP Trunk to SME.
- SME uses the Route Pattern to match this call to the Route List and then to the Local Route Groups LRG-LOCAL and LRG-REMOTE.
- With Standard Local Route Group, SME lookup the device pool DP-US-SITE of the SIP Trunk pointed to US-CUCM that received the call.
- Since the Local Route Group LRG-LOCAL is set to NONE.
- SME uses the second Local Route Group LRG-REMOTE and finds the Route Group RG-US-SITE.
- SME selects one of the SIP Trunks contained in the Route Group RG-US-SITE which are Trunk-To-GE-CUCM and Trunk-To-AU-Site.
- For example SME selects the SIP Trunk to GE-CUCM and sends out the call to it.
- GE-CUCM uses the Route Pattern to match this call to the Route List RL-CMS then to the Local Route Groups LRG-LOCAL and LRG-REMOTE.
- GE-CUCM uses the device pool of the SIP Trunk to SME that received the call DP-US.
- In the device pool, the LRG-LOCAL is set to RG-GE and the LRG-REMOTE is set to NONE.
- Finally GE-CUCM selects one of the SIP Trunks contained in the Route Group RG-GE which are Trunk-To-GE-CMS1 and Trunk-To-GE-CMS2.
- For example GE-CUCM selects the SIP Trunk to GE-CMS1 and sends out the call to it.