License Fees For Enterprise Telephony – Part 1


Software licenses are required to run modern telephony and unified communications solutions. The first of two posts give you tips on how to plan the core elements to minimize license costs.

The second article describes costs for networking with other systems, cross-site networking, conferences, upgrades as well as maintenance and service fees.

A modern telephony and unified communications solution includes telephony servers, gateways to different networks and services, session border controllers (something like a VoIP-specific firewall), hard phones, softphones, management tools, etc.

Depending on device features, functions, and equipment, licensing costs to depend on following factors:

License Fees for Hardware and Devices

The type of the device (telephony server, presence server, multimedia gateway, …) determines the number of license costs substantially.

Redundancy of servers and gateways is important to increase the availability of the overall solution. This will increase license costs.

Tip: for a few solutions, cost depending on the number of users to be switched to the redundant system.

If you already use server virtualization solutions, it may be useful to have licenses for the virtual operation of a telephony server. This eliminates hardware costs.

The choice of the housing type (stand-alone, wall or rack mounting) can lead to different license costs.

Voice and video quality depends on many factors, but especially on coding technology. Since special hardware (for example loudspeaker, microphone, gateways) is required, special license costs for these techniques are also to be paid.

License Fees for Features and Functions

License costs are mainly dependent on features and functions of the solution. Define which telephone services you need. Consider how call control should look like. Define the number and type of devices to be supported per workstation and the number of devices per user. Software packages, e.g. Presence, Computer Telephony Integration (CTI), hotel modules, call centers, etc.) are mostly paid. They typically pay per user.

For voice calls the number of simultaneous audio channels or conversations as well as the type of audio connections (static, dynamic), especially in case of announcement systems or alarm servers, is price-determining.

Access to directory services (via different data sources) to manage contact data and search in different directories/databases is a modern feature, which, however, can cause high license costs, depending on the number of users.

Telephone directory access via Web services is available, but often causes costs.

The integration of the solution with Microsoft Exchange servers is usually desired by many customers today. This function is cost-effective for many solutions.

Voice Messaging (voice mailbox) licenses depend on the recording capacity per mailbox, the total number of mailboxes, the total storage capacity of all mailboxes, as well as the number of alarm announcements for alarm servers. If the mailbox system is a separate hardware unit, the maximum number of parallel interfaces to the mailbox system is cost-effective.

Many companies use fax servers. Above all, the number of users and the simultaneous channels determine the license costs.

Ask your supplier about whether services such as voice prompts or voice controls (e.g., dial “1” for support, “2” for sales, “3” for etc) will cause costs.

License Fees for Interfaces

Determine the number and type of interfaces of a device. The number of ports per module affects the license costs. This can cause additional costs at the latest when expanding a solution.

Tip: When you select the solution, you should consider expansion modules and the associated upgrade costs within the next following years.

The supported interfaces to the provider side are often ISDN basic and primary rate access interfaces, analog ports (Foreign Exchange Office, FXO, Foreign Exchange Station, FXS) or Ethernet (SIP trunks) to the provider.

Tip: in many countries the ISDN technology is going to be replaced by Voice over IP technology. The question arises whether an investment in ISDN licenses still makes sense.

Universal Serial Bus (USB) interfaces are used to attach a keyboard, mouse, screen, memory, dongle, etc. Video interfaces (such as Digital Video Interface (DVI), High Definition Multimedia Interface (HDMI), DisplayPort, Video Graphics Array (VGA) and others are required to attach monitors or video cameras, for example, and may not affect the license costs.

Subscriber cards to attach analog, digital or IP terminals require their own licenses. In many cases the amount of license fees depends on the maximum number of supported users per card or interface.

Option cards (for optional extensions such as DECT base stations for cordless phones, Voice over IP communication, analogue or digital fax transmission, voicemail, internetworking of telephone solutions, etc.) cause additional license fees.

The size of required internal system memory (RAM) and hard disk capacity depends on the file size of software images and configuration data. This results in additional costs. The dimensioning is usually carried out by the supplier.

If you want to use cordless telephones, you have to pay license fees for DECT base stations or WLAN access points as well as for their attachment to the telephony solution. The use of integrated or external antennas may also affect the cost of the software.

Tip: because license costs in this area may depend on the number of simultaneous calls and/or the number of supported devices, you should define these parameter values.

 Tip: ask for bundle offers. These usually include base stations and clients and thus help to save costs.

Licenses for Terminals

Define the number and type of terminals (the extensions or call stations, which you expect in the foreseeable future, the number of SIP devices as well as the SIP accounts). This can be important if you want to attach SIP terminals of alternative manufacturers to the solution.

Tip: find out whether the solution supports products of alternative vendors, and if so, to what extent.

Since there are different versions of soft clients (phone software for a desktop computer, but also for a smartphone), you should define exactly how many licenses you need for your computers (depending on operating system).

The number and type of mobile clients for in-house radio systems (such as DECT or WLAN) or public mobile services (such as GSM, UMTS or LTE) determine the license costs for this terminal group.

If your solution still supports analog or digital faxes, specify the quantity and device standards (Group 3, Super G3, Group 4) to be supported.

The following article describes costs for interworking with other systems and across sites, conferences, upgrades, maintenance and service fees.

About the author:

Ronald Schlager is independent trainer, consultant, and blogger about communications technologies and their applications.

Ronald Schlager´s profiles:

Ronald Schlager´s Bio, LinkedIn, TwitterXing

Image credit:, artist: geralt