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This page covers specific aspects of a Cisco UC520 installation for a proposed Cisco Certified UC520 Installer.  It covers questions and topics that often come up during the installs, and is designed to speed up installation.  It is targeted to an install engineer that only needs to make minor changes to the system.


Q: How do you determine UC520 model from part number or bill of materials?

For up to 8 Phone Users

ModelBoM RequirementsCisco Part Number
UC520-8UFXO analog trunks

BRI trunks



UC520W-8UFXO, integrated wireless

BRI, integrated wireless



For up to 16 Phone Users

ModelBoM RequirementsCisco Part Number
UC520-16UFXO analog trunks

BRI trunks



UC520W-16UFXO, integrated wireless

BRI, integrated wireless



CE520Add 8 Ethernet portsWS-CE520-8PC-K9

For up to 24 Phone Users

ModelBoM RequirementsCisco Part Number
UC520-24UFXO analog trunks to PSTN

BRI digital trunks to PSTN



CE520 (2)Add 16 Ethernet portsWS-CE520-8PC-K9
AP-521 (1-3)Autonomous AP only to extend coverageAIR-AP521G-x-K9

For up to 32 Phone Users

ModelBoM RequirementsCisco Part Number
UC520-32UFXO analog trunks to PSTN

BRI digital trunks to PSTN



CE520Add 24 Ethernet portsWS-CE520-24PC-K9
WLC (1)Centralized WLA, future scalability, roamingAIR-WLC526-K9

For up to 48 Phone Users

ModelBoM RequirementsCisco Part Number
UC520-48UOnly FXO analog trunks

Only BRI digital trunks

T1/E1 and FXO trunks

T1/E1 and BRI trunks





CE520 (2)Add 48 Ethernet portsWS-CE520-24PC-K9
WLC (2)Centralized WLA, future scalability, roamingAIR-WLC526-K9

Q: What are the differences within product line and user limitations imposed by each model?

UC520 Model Differences

Product (UC520 Model)DifferencesIP phone-User Licenses
UC520-8UCisco Unified Communications Manager Express, Cisco Unity Express, 4FXS, 1 VIC slot, 4FXO or 2BRI (two models)10
UC520W-8UUC520-8U with an integrated autonomous wireless (two models)10
UC520-16UUC520-16U with an integrated autonomous wireless (two models)18
UC520-24UCisco Unified Communications Manager Express, Cisco Unity Express, 1 VIC slot, 8FXO or 4BRI (two models)24
UC520-32UCisco Unified Communications Manager Express, Cisco Unity Express, 1 VIC slot, 8FXO or 4BRI (two models)36
UC520-48UCisco Unified Communications Manager Express, Cisco Unity Express, 1 VIC slot, (12FXO, 6BRI, 4FXO and one T1/E1, or 2BRI and one T1/E1 (four models)52

Q: What is the Role of FXO ports in design, and their cabling and termination requirements?

Role of FXO Ports: A device that bridges a network/the Internet to an analog phone line. It essentially converts the VoIP (digital) signals to telephone (analog) signals (and vice versa).

Design: A business voice network is connected to PSTN via a group of lines known as trunk. A trunk to PSTN uses two types of telephony interfaces:

- Analog—FXS, FXO, Analog DID, E&M, and CAMA

- Digital—BRI, T1 CAS, E1R2, and T1/E1 PRI

  • In the form of a trunk, an analog connection can carry only one call over each physical connection. Hence, analog connections provide low-density PSTN connectivity.
  • BRI provides an alternative for low density connectivity by carrying only two calls per physical connection. BRI is the only low-density digital PSTN connectivity.
  • High density PSTN connectivity usually requires a digital connection such as T1 CAS, E1R2, T1/E1 PRI, or QSIG. A high density digital trunk contains multiple channels and can carry multiple calls over each physical connection.
  • Cisco recommends a ratio of 4:1 (users-to-PSTN channels) for number of PSTN trunks. UC520 has models with various fixed interfaces for PSTN trunk connectivity, such as FXO, BRI, and T1/E1. Analog DID is also supported by adding a 2-port or 4-port FXS/DID card in the VIC slot.
  • Below is a summary of the PSTN trunk capacity of applicable UC520s:

PSTN Trunks Capacity of UC520 Models

UC520 modelPSTN InterfacesNo. PSTN-VoIP channelsNo. PSTN-VoIP channels
With FXO or BRIWith E1
UC520-8UFXO(4), BRI(2)4NA
UC520-16UFXO(4), BRI(2)4NA
UC520-24UFXO(8), BRI(4)8NA
UC520-32UFXO(8), BRI(4)8NA
UC520-48U No T1/E1FXO(12), BRI(6)12NA
UC520-48U With T1/E1FXO(4), BRI(2) and T1/E1430

Cabling & Termination: In the diagram below, UC500 supports four (4) PSTN FXO ports to connect to a Telco or PBX circuit


  • Connect one end of the included RJ-11 telephone cable to the unit’s FXO port. Connect the other end to your telephone wall jack.
  • UC500 supports FXO Answer and Disconnect Supervision. See: [1]

Q: What is the role of FXS ports in design and knowledge of feature code support for handsets?

FXS Role: A device that lets you connect an analog telephone to it and make calls over a network or the Internet. This is basically an analog telephone to VoIP converter (and vice versa).


  • UC500 supports four (4)  RJ-11 POTS (Plain Old Telephone Service) FXS ports to connect existing analog phones or fax machines.
  • If power is lost to the unit or Internet service is down, calls can be redirected to a traditional carrier via the FXO interface.

Q: What are the Wireless speeds, channels and encryption methods available to onboard models?

  • UC500 has Optional WLAN AP.
  • The 802.11b/g integrated access point can be used to provide integrated WLAN connectivity to mobile clients - voice and data - resulting in mobility and enhanced productivity for users.
  • Follow the guidelines of up to x3 7921 IP Phones per AP.
  • Speeds: The integrated 802.11b/g access point in the Cisco Unified Communications 500 Series supports up to 54 Mbps connections.


Encryption Methods: Enhanced security is provided with support for:

  • Wi-Fi Protected Access (WPA and WPA2), including authentication with 802.1X and Cisco LEAP
  • Protected Extensible Authentication Protocol (PEAP)
  • Dynamic Wired Equivalent Privacy (WEP); or
  • Static WEP
  • WLAN VLANs and 802.1q/e are also supported which prioritizes voice/video traffic with queuing.

Note: Optionally, use autonomous APs or Unified Wireless Solution with WLAN Controller 500. AP500 expansion module can be used to support up to X wireless users. WLC500 expansion module can be used to support 1-8 AP500s.

Q: What is the default addressing and VLAN numbering used on system if specifics are not requested ?

  • UC500 design uses only 2 VLANs:

1) Voice devices on the Cisco Voice VLAN (assigned the value of 100) and 2) Data devices on the Cisco Data VLAN (assigned the value of 1).

  • When AP-521s are used to expand the WLAN, VLANs are assigned in same manner as with the integrated AP. The design continues to use only two VLANs by manually synchronizing VLANs between the WLC-526 and UC520.

Q: What are the Music on Hold (MoH) options, and what is the supported file format/s if streamed from Flash?

  • The MoH file can be any audio file recorded by an end customer. You can record your own MoH file and upload it on flash. The MoH file can either be .au or .wav extension, however, the format must be CCITT u-law (or a-law), 8Khz, 8bits, Mono. The supported file formats are also covered in the pre-requisite section of CME MoH document: [2]
  • Each recorded MoH minute is about 500K. There is no max - it depends upon the available space on flash.
  • There is a built-in MoH file in UC500.
  • Note: In general MOH is not going to be of the same quality with G729 codec as compared to G711 as it has higher compression than G711 & also the compression algorithm in G729 is best suited for human speech.

Q: What are the differences between routed and switched ports, and when and where should they be used?

Q: What wired, wireless and software based handsets can be used and what are their line count limitations?


  • The Cisco Unified IP Phone Expansion Module 7916 extends the capabilities of the Cisco Unified IP Phones 7962G, 7965G, and 7975G with additional buttons and an LCD display.
  • With this expansion module, you add 12 physical keys with access to 12 additional keys via the page keys for a total of 24 buttons to the existing six buttons of the Cisco Unified IP Phones 7962G and 7965G and the existing eight buttons of the Cisco Unified IP Phone 7975G. You can use up to two Cisco Unified IP Phone Expansion Module 7916s with Cisco Unified IP Phones 7962G, 7965G, or 7975G.

Demo VOD: SBCS phone portfolio overview - This SBCS Tutorial VoD gives an overview of the phones supported in SBCS. It highlights the various features each phone supports.

Q: What are the Basic and Primary Rate interfaces, channel capacities and cabling type to NT1 or NTU?

Q: What expansion devices are available in switches, routers, wireless and mobility?


Q: How do you connect to the system via serial console, and what are the speed and cabling requirements?

Demo VOD: How to access UC520 command line interface - This SBCS Tutorial VoD describes how to get access to the IOS command line interface using Telnet and serial console cable. In order to configure UC520 using IOS CLI, users must first gain access to the console and CLI.

Q: How do you confirm system clock and time-zone are correct, and manually set time if required?

Q: How do you confirm operational status of interfaces (e.g., administratively down, down, up or err-disable)?

Q: How do you confirm configuration of DHCP pools and exclusion ranges, and how do you remove if required?

DHCP – IP Addressing Scheme

DescriptionIP AddressAssignment Method
WAN interface of the main office UC520100.100.1.2/24From ISP
WAN interface of a home office (optional) ISP
VPN network between main office and home offices (optional) - (from main office UC520)
Main office Cisco Data VLAN (1) (two models)Static
Main office Cisco Voice VLAN (100)
Main office servers, Management VLAN of WLC-526192.168.10.1/24 -
Main office data end points192.168.10.11/24 -
Main office voice end points10.1.1.11/24 -
VPN Tunnel endpoints at remote location (optional) -
Home office endpoints (connected to Cisco 871w) - optional10.10.10.1/29 -

Q: What is the role of system message, what are the display locations on handsets and how it is changed?

Q: How do you install handsets, messages button and use local and system speed and fast dials?

Q: How do you set up directory numbers, and what is the difference between description, name and label fields?

Q: How do you set up call forwarding options, busy, no answer with timeout and night service?

Call Forwarding: Diverts a call to an alternate answering point based on a specific condition such as no answer, busy, all calls, or night service hours.

Q: What is Night service, where does it fit in, and what are the configuration requirements for enabling or disabling manually?

Q: How do you confirm handset MWI number on and off functionality, defaults unchanged from templates?

Q: How do you map directory numbers to handsets, and what are normal, silent, monitor and overlay lines?

Q: What are the Hunt group types - including peer, sequential and longest-idle - and their configuration?

Call Hunt Group: When a call is placed to a specific extension it is sent to multiple phones in a group, often in a preferred order, until the call is answered.

Q: How many hours of voicemail storage are provided with the various density UC500 Series platforms? 

Cisco Unity Express has about 14 hours of recording or storage time, with 8 to 14 minutes per mailbox.

Moves, Adds and Changes

Q: How do you create a directory number within local number pattern, and confirm non-conflict?

Q: How do you create handsets up to user limit, and verify type and MAC address?

IP Handsets

Analogue Handsets

  • Four analog telephony ports (FXS) are provided the 8-to-16 user model of UC520; and optionally can be added on VIC slot of 32-to-48 user model of UC520.
  • The analog devices, connected on these FSX ports, do not count against the maximum number of IP end points supported by the UC520. However, the number of analog devices is limited to four, which is the number of FXS ports fixed on the 8-to-16 user UC520 model and the VIC-4FXS voice card used in the VIC slot of 32-to-48 user model of UC520.

Q:  How do you modify call forwarding options, and when and where to prefix with a 0?

Advanced Features (above the basic installer requirement):

Q: What is the role of Unified CallConnector, and what functionality is gained from a client installation and server installation? What are the different requirements?

UCC Client

  • The SBCS solution allows you to add the Unified Call Connector (UCC) application. This gives you the ability to click to make a call and a 'pop up' will tell you the details of anyone who calls.
  • You can search and dial from a contact list. This is particularly useful if you've got a customer waiting on the line and you're trying to find someone to help.
  • There is also the ability to dial from the web.
  • Users will be able to utilize Single Number Reach capabilities.

VOD Demo: Cisco Unified Call Connector Client Install - This SBCS Tutorial VoD details how to setup and install a UCC client. The VOD also covers how to use some of the features available with UCC client such as click-to-dial, magic wan and inbound screen pop-up.

UCC Server

  • The optional Call Connector Server application enables 'presences' - it gives users the ability to see whether their colleagues are online and if they are free to make a call or out of the office.
  • When you need to bring another person in on a call, you can quickly and easily see who is available and instant message them or conference them in. You can call, email, send an IM or just leave a VM and by knowing someone's location or activity, it enables you to decide the best way to communciate with them.
  • This is a very powerful application which helps promote effective team working.

VOD Demo:

  • Cisco Unified Call Connector Client Server Mode - This SBCS Tutorial VoD details how to setup and install a UCC client to operate with a UCC server. It highlights some of the features available to the UCC client when operating with a UCC server, such as having access to IM, presence, and call logs.
  • Cisco Unified Call Connector Mobility Solution - This SBCS Tutorial covers the Cisco Unified CallConnector Mobility solution. The Cisco Unified CallConnector Mobility solution enables small businesses to have a mobility solution for their employees. Some highlights of the solution include Single Number Reach (SNR) functionality, presence and location status across multiple sites, and the ability to make business calls remotely. The solution increases mobility for the workforce while reducing missed opportunities with a Single Number Reach number.

Q: When are multisite VPN tunnels supported, what number is supported by hardware, and what is the concept of extension uniqueness?

Q:  What is the role of Arc Express and functionality gained (though not fully supported at this point) ?

Q:  Do you support Nokia E-series integration?

  • Yes. You have to purchase the Nokia Softphone license, NOK-SCCP-CME-01 or -05, but not the UL for UC500 customers. The number at the end (01, 05) indicates the number of user licenses that are provided, with one user license required per Nokia Dual Mode Phone.
  • This client enables the Nokia E-Series Dual mode phones to register through the Wireless LAN with CME.
  • The Nokia dual mode phone does support a forward to cellular function from an IP voice session.  But this is a manual process, not automatic. Nevertheless, you are able to use one phone to connect either to the cellular network or to the VOIP network.....still an attractive capability. If you couple this with SNR capabilities provided by UCC Mobility, the user achieves a lot of convenience and efficiency in the way they make and receive phone calls.


Q:  What Monitoring tools are offered by Cisco (Cisco Network Monitor?) ?

Q: What Automated Attendant features are supported, and what is the affect on call flow?

  • CUE auto-attendant allows for menus as wide and deep as wanted by the customer.
  • The instructions to customize the CUE AA can be found at: [4]

Q: Is Fax to email supported, and how do you install (via app_faxmail_onramp script)?

  • Fax to email requires CUE 3.0.3 which is bundled in UC500 Software Pack 4.2.7. The SBCS Solutions page on Support-wiki has link to the latest software for all the SBCS components: [5]. Please make sure that you have min. CCA release 1.6 to perform the upgrade.
  • Sample of how to configure the fax to email feature: [6]

Q: How does the Cisco Unified Communications 500 Series scale its capacity? What is the upgrade path?

Scaling Capacity

  • The Cisco Unified Communications 500 Series expands in voice ports through the Cisco Catalyst Express 520 companion switch(es).
  • Every UC500 configuration comes with 8 phone licenses, even the 16, 32, and 48-user configurations. For the 16-user configuration to utilize the additional 8 phone licenses, the 8-port Cisco Catalyst Express 520 must be connected to the Cisco Unified Communications 500 Series. For the 32-user Cisco Unified Communications 500 Series solution, the 24-port Cisco Catalyst Express 520 must be connected to the Cisco Unified Communications 500 Series. Similarly, for the 48-user Cisco Unified Communications 500 Series solution, two 24-port Cisco Catalyst Express 520 Switches must be connected to the Cisco Unified Communications 500 Series unit.
  • User count on a given configuration determines the maximum number of users supported. For example, an 8-user configuration does not support more than 8 IP phones, even with the Cisco Catalyst Express 520 connected. If a customer plans to grow beyond 8 ports, the customer should initially order the 24-user configuration and add the Cisco Catalyst Express 520 when needed to support additional ports.

Upgrade Path

  • A software license upgrade is required to upgrade from 8-user system to a 16-user system. This (as well as upgrade from 32-user system to a 48-user system) is now available. The upgrade from 16-user system to a 32-user system requires hardware upgrade. A TMP credit program is available to assist with hardware upgrade from 16 to 24 user or larger.
  • The 8/16 UC500 can’t support more users due to hardware on the box. This means you have to position with some customers to buy the 24 user to start, others who are price sensitive, will have to do an upgrade.

Q: Does the Unified 500 Series have DSP limitations? 

Yes. Each UC500 SKU comes equipped with a default DSP configuration and is not upgradeable in the field. Both 8- and 16-user SKUs comes equipped with two (2) 5510 DSPs. The 32- and 48-user SKUs both come equipped with four (4) 5510 DSP configurations.

Q: Can multiple systems be networked together? 

  • Yes, Multi-Site deployments are supported on UC500. A max. of 3-5 sites is recommended. If there is a requirement for additional site-to-site networking, it is recommended that you deploy the Integrated Services Router family for those scenarios.
  • With a Multi-Site deployment, you will be able to do 4-digit dialing as well as enable long distance calls over the data network.
  • Multi-site deployments may be done by setting up VPN session between UC500s. The idea is to enable communication between the UC500s. As long as you have IP connectivity between UC500s, you will be able to have 3-digit or 4-digit or 5-digit, etc dialing.
  • VPN session provides you with a secure way of communicating and thus is recommended. Generally, the inter-site VPN sessions are established by a WAN router. You can enable QoS on UC500's WAN interface.
  • It appears in your deployment Microsoft software virtual VPN application is used for connecting workstations from one site to another - this won't help in setting up a session between UC500s.
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