Our firm has begun to use Office Communication Server for instant messaging. We were using MSN Messenger but there was underlying concern about using a personal instant messenger for Business Communications.
Yahoo, MSN, AOL, and other instant messenger programs are not secure. Therefore if you send messages with confidential client information you are potentially allowing your client’s information to get stolen. I know many firms that use these type of instant messengers and this can leave an open door for a breach of client confidentiality.
Office Communication Server is completely secure so when I am at a client’s office and ask my assistant through communicator what is the admin password for the client’s server, I do not have to worry about that information being leaked to the entire world.
OCS give us three ways to connect:
1. Through Software downloaded on the workstation.
2. Through a web based portal available in Internet Explorer and Fire Fox.
3. On a Windows Mobile or Blackberry Device

Tight Outlook Integration
1. Conservations are archived and can be searched in outlook.
2. Easily allows you to send an Email Message through Communicator
3. When replying to an email in Outlook, you can send it as an instant message
4. Communicator will look at your Outlook Calendar and set your Availability Status depending on your appointments.
Advantages:
- Can send attachments through a secure network. Attachments in Emails are not secure. Ours allows files up to 50MB and is faster then an attachment on an email.
- Can be used with VOIP and Video Conferencing
Disadvantages:
- Can only communicate with OCS Users
- Available only on Windows Mobile and Blackberry. Not on I-Phone or Palm Based devices.