Case Study (Corporate Headquarters)

HQ Design Description

  • At the Access Layer, the data network is providing power to the IP telephones using in-line power modules.  The Access Layer switches are Catalyst 4006 which contain 48 port 10/100 Fast Ethernet in-line power modules. The in-line power modules require an Auxiliary DC Power Shelf, a 1050W Catalyst 4000 Auxiliary Power Supply Unit, and a Power Entry Module for the chassis power supplies.   UPS systems are recommended in the wiring closets and data center to provide continuous power in the event of a power failure, maintaining high availability of the voice and data network.  
  • The IP telephone will not occupy an additional data network port.  The user workstation will be connected directly into the switched port on the IP telephone.  
  • The 4006 Access Switches (Layer 2) are dual homed to Core Catalyst 6509 Switches (Layer 3). There are 36 floors with 2 IDFs per floor, each containing a single 4006.  There will be (4) four 6509 (Layer 3) switches deployed as core switches to aggregate all of the Access Switches. 
  • HSRP will be deployed in the core switches to insure L3 default gateway redundancy. HSRP priority will be used to force voice traffic over one Gigabit uplink, and data over the second Gigabit uplink for each closet switch.  
  • Port Fast will be enabled in the access switch ports connected to the phones. This will reduce the time required for the phones to register with Call Manager.  
  • The Core Switches will be dual homed to (2) two Catalyst 6509s acting as PRI/T1 voice gateways to the PSTN. Each core 6509 chassis will have one (1) SUP2 with MSFC2 and PFC2 module. These (4) four switches will also provide connectivity for the CallManager Cluster components, 6509 FlexWans providing WAN connectivity, and VG248s for FAX/Modem support and existing Voicemail.
  • The voice PRI/T1 circuits will be divided evenly between two redundant Catalyst 6509 voice gateways. Each Catalyst voice gateway will have two (2) SUP2 with PFC2 modules for redundancy.  
  • Each Catalyst 6000 Voice T1 module has 8 ports. Each individual port on this module can be configured to support either a T1 or PRI.  The Catalyst 6000 Voice T1 modules will be provisioned on each of the two (2) 6509 chassis acting as voice gateways.  The voice PRI/T1 circuits will be distributed evenly to each Voice T1 module.  The unused ports on the Voice T1 module can be used for conferencing and/or MTP transcoding.
  • Additional Voice T1 modules were provided for hardware based conferencing.
  • The CallManager Servers are connected to the (4) Core Switches in a distributed manner to minimize the impact on call processing of a single Core Switch failure.  
  • Six (6) VG248s will provide 288 analog FXS ports for connectivity to the vmail servers. SMDI signaling will be received by the Lyrix server via the VG248. CallManager will communicate voice messaging information to the VG248 via skinny protocol. Connectivity of (6) SMDI links from vmail server to each VG248 will be tested. This architecture can potentially provide the most SMDI redundancy. Alternatively, a single SMDI cable will be connected from Lyrix to a single VG248, and then daisy chained across the 6 VG248s.  
  • Each data/telephone closet will have cross connects to the data center via Cat 3 riser for analog station ports. This will enable placement of (22) VG248 Analog voice gateways in the data center to provide FXS ports to support 1,056 analog stations distributed throughout the building. The VG248 will support Fax Relay and Modem Pass-Through in additional to analog handsets and potentially Polycom speakerphones.  
  • Two (2) 3662 gateways will be deployed to provide analog gateway capability for 48 FXO ports. These trunks will be used in the event that all digital trunks are unavailable due to a SONET ring failure. These analog trunks can also be used for overflow in the event that all digital trunks are busy.  
  • One (1) 3662 gateway with a total of (16) FXO ports will be provided to serve MN and CF. (8) FXO ports will be dedicated to each entity. These trunks will be used in the event that all digital trunks are unavailable due to a SONET ring failure. These analog trunks can also be used for overflow in the event that all digital trunks are busy.
  • MN and CF are provided with 2 dedicated PRIs each for billing purposes. These entities will utilize CallManager for call processing and the 6608 gateways, however, they will be restricted to their dedicated PRI facilities. There will be no 5 digit dialing capability between these entities and HQ users. MN and CF users will be served by the common voicemail system. Partitioning of voicemail server to serve these users is not a requirement.
  • Thirty eight thousand (3,800) Agilquest hoteling users will be supported via the extension mobility API. It should be noted that the 7910 phones will not support extension mobility (Agilquest hoteling).  
  • Music On Hold is not required, so no additional servers are provided for this capability.