Every major IP PBX vendor builds a proprietary softphone that is customized to tap into its back-end system like no other standards-based Session Initiation Protocol endpoint can.
The use of these proprietary methods both stymies the interoperability between vendors and limits the number of third-party companies that will develop softphone applications for a given vendor’s system. Therefore, it’s legitimate to ask what you gain by going proprietary. We took a look at the two softphones Alcatel – Lucent offers with its OmniPCX Enterprise IP PBX to help quantify the proprietary advantage.
Overall, the major advantage of vendor-specific softphones is their ability to access the full feature set of the underlying PBX. Standards-based softphones are limited to features defined within the protocol and not the underlying VOIP system. A second advantage is ease of use; the softphone functions the same as the vendor’s hard phone so the user learning curve is nearly eliminated.
Alcatel-Lucent’s My IP Touch (we examined Version 220.127.116.11) is a graphical representation of the company’s IP Touch 4068 hard phone that can be installed on any Microsoft Windows computer. The application requires less than 50MB of hard disk space and works with the minimum standard PC specification on the market today. The softphone, like a hard phone, is licensed as an individual device.
Once installed, the user registers with the OmniPCX Enterprise and is given an extension and the permitted telephony features. To place a call, the user clicks on the handset on the screen and selects the numbers. The buttons on the display portion of the softphone change according to the call state. So, for example, if a user were to go off hook and place a call, once connected, a previously blank button would display the transfer option. The user could click on transfer and enter the desired number.
Volume controls, message waiting indicator light and the full qwerty-based keyboard layout also are shown in the display. The keyboard represented on the computer screen lets users perform directory lookups and send messages to another user’s phone while either party is on another call.
All of the OmniPCX Enterprise’s more than 500 call features, such as account code charging, call park and call pickup, are available to softphone users. There is a second skin — a different representation of My IP Touch softphone — that takes up a smaller footprint on the user’s desktop while still providing full functionality.
As with any softphone, performance is heavily determined by the underlying PC platform. Our test system comprised a Pentium M processor running Microsoft Windows XP SP2, 1GB of RAM, and integrated microphone and sound card. A headset is recommended for optimal sound quality and performance, but even with the built-in microphone and speakers on the test laptop, sound quality was acceptable and latency was less than 100 msec.
Alcatel-Lucent’s My Phone (we tested Version 3.295.30) is part of the larger OmniTouch Unified Communication software suite. My Phone can be installed as a thick client, referred to as the 4980 softphone, or accessed via a Web page running off the OmniTouch server (Alcatel-Lucent’s telephony application server). Using the fat-client option, the softphone can be integrated with Microsoft Outlook, Outlook Web Access, Lotus Notes or Lotus Web Access, giving users access to the basic telephony function from their e-mail client.
When accessing the My Phone Web client from a secure SSL browser connection, a small plug-in is downloaded to enable VOIP . This plug-in is unloaded when the browser is closed, so that it can be used at public terminals with no fear of leaving behind corporate information. Users can specify if they want to use their PC for the voice path or specify an alternative number, such as a home phone or cell phone.
The Web client can be run in a “full window” or “phone bar” mode, and can operate on its own or be embedded in a corporate portal page. Both versions display the call status and incoming calls, as well as buttons for such common functions as conferencing, recording, transferring, dual-tone multifrequency (DTMF) and call hold. Also displayed are buttons for such functions as speed dial, call logging, customization and voice-mail access. The full window modes show the call log, director service, personal phone book and a DTMF keypad. The Web client also can provide telephony-based presence information to other Alcatel-Lucent softphone clients.
The other advantage of proprietary softphones is their tight integration with the underlying PBX. From the My Phone application, users can launch a tool that shows them a graphical representation of their physical hard phone set. They can arrange their button mappings for features and speed dials without having to contact an administrator. The mappings carry over to their softphones as well.
Changes such as activating call forwarding or do-not-features made in the Web interface are reflected on the hard phone and the thick client. The reverse also is true: Features activated on the hard phone show up in the softphones. The 4980 fat client can change how voice paths are routed on the fly. During a call, users can switch the voice path from VOIP to a public switched telephone network phone, desk phone or a cell phone.
The user preprograms an alternate number at which the PBX can reach. When this feature is activated, the OmniPBX Enterprise initiates a call to the specified alternative number, establishes a connection, then internally bridges the call in progress.
Testing the waters of open source softphones
Michael Hommer and Robert B. Tarpley
In our test of two Session Initiation Protocol -based freeware softphone options — PortSIP and Phoner — we required them to register and place calls via both freeware Asterisk 1.2 and Zultys MX 250 Enterprise Media Exchange IP PBXs.
Several other open source softphone projects are flourishing on the Internet. In general, the feature sets tend to be simplistic compared with commercial SIP-based and proprietary offerings, but if basic telephony is all that is required, and you have the expertise to support them within your organization, these might fit the bill. We selected two projects that had generally positive reviews from the Internet community and also could be used as a SIP endpoint on an IP PBX.
PortSIP is sort of a hybrid open source softphone. The softphone itself is free and can be downloaded from the project’s Web site, which also offers a software development kit (SDK) and sample code for download. The catch on the SDK and code is that it will only allow three-minute voice conversations. The unrestricted SDK can be purchased along with technical support to allow for private labeling and custom user interfaces.
The PortSIP softphone runs on Microsoft Windows 98, 2000, XP and 2003 machines. Installation and registration were straightforward with both PBX systems. It can support as many as five phone-line appearances. The feature list is brief: call hold, call transfer, three-party conferencing, do not disturb, auto answer and redial. It also can record calls locally as a WAV file. The standard codecs (G.711, GSM, iLBC, G.723.1, G.729) are supported as well as video -delivery standards H.263 and H.264.
Audio quality was on par with the other softphone tested, though to use the headset we had to manually configure the audio device to be used. Latency on our test system was less than 100 msec. T