Endpoint Performance
While the user interfaces for both hard devices were very functional and intuitive, the performance was a mixed bag. The one-way latency for calls placed between two IP phones or two USB handsets with no added WAN delay was 220 ms. Rather high, but these were reference designs.
It was interesting to note that when the USB handsets were removed from the equation and measurements were taken directly between two soft clients, the one way latency was 145 ms, just under the ITU recommendation of 150 ms. When we asked Microsoft about this, they said it had to do with the USB drivers and USB protocol itself.
The sound quality with the RTA codec was very rich. RTA is a wideband codec and the phones were designed with appropriate speakers and microphones to take full advantage of the increased dynamic response range of a wideband codec. No issues with jitter or the speech quality were found while testing, but, as mentioned, latency was slightly noticeable.
Management
Since OCS is tightly integrated with Active Directory and Exchange, management is somewhat already built in. User management is handled within Active Directory as described above. Voice mail is part of the user setup in Exchange, again just an additional step in the usual Exchange user setup process. Trunks, dial plans and general configuration settings are all compiled in a single Microsoft Management Console for OCS. In a single view, an administrator can quickly see all the servers in the environment and their status. It uses the MMC framework that all Microsoft administrators are familiar with, so the learning curve is quick.
Voice Mail
Voice mail is stored on the Exchange server. Administrators must define a Unified Messaging Mailbox policy which sets the basic parameters: greeting length, automatic email messages and PIN settings. PINs can be assigned or automatically generated and sent to the users via email. Text can also be appended to voice mail and fax notifications. Different policies can be applied to different users.
Licensing and Cost
To install OCS, you need a copy of Microsoft Office Communications Server and a CAL (Client Access License) for each user. For most customers, the CAL costs $21.48 per license and $5.40 for 1 year of software assurance. The Standard servers cost $487.56 for the license and $121.92 for 1 year of software assurance per server The Enterprise server is $2,790.60 and $697.68 for license and software assurance respectively. To add voice mail, Unified Messaging would have to be added to the Exchange server.
On the client side, Office Communicator would need to be installed; the license is included with Office Pro Plus 2007 and Office Enterprise 2007. No additional user licenses are needed for Exchange or SQL.
Conclusion
With OCS, Microsoft has rolled out the foundation for integrating voice into the daily work flow of the office user in a similar manner as users employ instant messaging and email now. The addition of contact-based presence allows users to ensure they are available to communicate with who they want, when they want; this increases their ability to be productive.
OCS 2007 is not going to replace your PBX for large enterprise environments, as it lacks some of the basic features such as call park, group pick-up and music on hold. It also provides alternative means to accomplish other basic features. For example there are no “speed dials;” you simply click on a frequent contact and place a call.
But the degree of integration into applications will help further the push of voice away from how it has always been done and into how it will be done in the future.
Robert J. Smithers is President and CEO of Miercom. With 18 years experience at Miercom, he has worked in testing, consulting and network planning as well as hands on implementations of networks.
Michael B. Hommer, Sr., Engineering Manager for Miercom, has spent more than 11 years in technology fields. Positions included Webmaster, IT Director and network consultant, designing and implementing global corporate infrastructures.
