Lync Online vs On-Premise Lync Server Understanding the Differences

The following matrix compares features across the delivery models for Lync Server 2010 (on-premises with or without federation), Lync Online with Office 365, and Office Communications Online (“OC Online”). 

Feature	Lync Server 2010	Lync Online	OC Online
IM and Presence
1-to-1 and multiparty IM/presence	Yes	Yes	Yes
Address book search	Yes	Yes	Yes
Distribution list (DL) expansion (DLX)	Yes	Yes	Yes
File transfers	Yes	Yes	Yes (inside firewall only)
PC-to-PC audio/video (A/V) dial-out calling	Yes	Yes	Yes (inside firewall only)
Click-to-communicate from Office applications	Yes	Yes	Yes
Interactive contact card in Office 2010	Yes	Yes	No
Lync skill search in on-premises SharePoint Server	Yes	No	No
Lync skill search in SharePoint Online	No	No	No
Persistent Group Chat	Yes	No	No
Privacy mode	Yes	No	No
Lync External Connectivity (Federation and Public IM Connectivity)
IM/Presence and A/V Federation with other organizations running Lync Server, Lync Online, or Office Communications Server	Yes	Yes	No
IM/presence and A/V federation with Windows Live Messenger	Yes	Yes	No
IBM Sametime federation	Yes	No	No
IM/presence federation with Extensible Messaging and Presence Protocol (XMPP) networks (including Jabber and Google Talk)	Yes	No	No
IM/presence with AOL and Yahoo	Yes	No	No
Meetings (A/V and Web Conferencing)
Meeting attendee capacity	250	250	No
Desktop sharing	Yes	Yes	No
Application sharing	Yes	Yes	No
White boarding and annotations	Yes	Yes	No
PowerPoint upload for online presentations	Yes	Yes	No
Upload for other Office file types	No	No	No
Polling	Yes	Yes	No
Multiparty PC-based A/V	Yes	Yes	No
Unauthenticated experience in Lync Web App	Yes	Yes	No
Unauthenticated attendee (rich client)	Yes	Yes	No
Authenticated experience in Lync Web App	Yes	No	No
Scheduled conferences (using the Online Meeting Add-in for Lync 2010 in Outlook)	Yes	Yes	No
Outlook delegation for scheduling meetings	Yes	Yes	No
Support for RoundTable conferencing device	Yes	Yes	No
Lobby	Yes	Yes	No
Interoperation with certified partners for dial-in audio conferencing	No	Yes	No
Provisioning for dial-in audio conferencing service for Office 365 direct customers	No	Yes	No
Phone dial-out from scheduled meetings via third-party dial-in conferencing service	No	Yes	No
Client-side recording and playback	Yes	No	No
Server-side recording and playback	No	No	No
Generate a link to a scheduled meeting via web page	No	No	No
Scheduling an online meeting in Outlook Web App	No	No	No
Dial-in audio conferencing on Lync Server	Yes	No	No
Multimedia content upload	No	No	No
Screen shot capture (including annotation)	No	No	No
Backstage/content preview for presenters	Yes	Yes	No
Mute all attendees	Yes	Yes	No
Mute individual attendees	Yes	Yes	No
Unmute all attendees	Yes	Yes	No
Unmute individual attendees	Yes	Yes	No
In-meeting attendee permission controls	Yes	Yes	No
Interoperability with on-premises video conferencing systems	Yes	No	No
Voice and Telephony
PSTN calling (incoming/outgoing calls)	Yes	No	No
Call hold/retrieve	Yes	No	No
PSTN dial-out for meetings	Yes	No	No
Advanced call controls (including transfer, forward, and simultaneous ring)	Yes	No	No
Access to Exchange Online voice mail	Yes	No	No
Team calling	Yes	No	No
Delegation for voice (for example, boss delegates to admin)	Yes	No	No
Call park	Yes	No	No
Outgoing Direct Inward Dialing (DID) manipulation	Yes	No	No
Enhanced 9-1-1 (E9-1-1)	Yes	No	No
Dial plans and policies	Yes	No	No
IP desk phone support	Yes	No	No
Survivable Branch Appliances for branch office resiliency	Yes	No	No
Call admissions control (CAC)	Yes	No	No
Support for analog devices (for example, fax)	Yes	No	No
Response groups	Yes	No	No
Private line (secondary DID for executives)	Yes	No	No
Interoperation with third-party private branch exchange (PBX)	Yes	No	No
Presence interoperation with third-party PBX	No	No	No
Remote call control (RCC) (also known as "click-to-call") with on-premises PBX	Yes	No	No
Malicious call trace	Yes	No	No
Unassigned number	Yes	No	No
Network Quality of Service (QoS) - Differentiated Services Code Point (DSCP)	Yes	No	No
Media path optimization	Yes	No	No
Phone number management	Yes	No	No
Call detail recording (CDR) and billing reporting	Yes	No	No
Integration with call center solutions (Aspect)	Yes	No	No
Client Support
Lync 2010	Yes	Yes	No
Lync Web App (for participating in scheduled meetings)	Yes	Yes	No
Lync 2010 Phone Edition (IP phones for Lync)	Yes	No	No
Lync 2010 Attendee client (for joining meetings)	Yes	Yes	No
Lync 2010 Attendant client (receptionist rich client)	Yes	No	No
Lync 2010 Mobile	No	No	No
Office Communicator for Mac	Yes	No	No
Office Communicator Web Access (2007 R2)	Yes	No	No
Office Communicator 2007 R2	Yes	No	Yes
Office Communicator Mobile (for Windows Mobile 6.x phones)	Yes	No	No
IM and media encryption	Yes	Yes	Yes
IM filtering	Yes	Yes	Yes
Anti-malware scanning for meeting content and file transfers	Yes (partner solutions)	No	No
IM archiving (server-side only)	Yes	No	No
Exchange and SharePoint interoperability
Presence interoperation with Exchange and SharePoint on-premises	Yes	Yes	Yes
Presence interoperation with Exchange and SharePoint Online	Yes	Yes	Yes
\[Exchange Unified Messaging](/news/agile-it-is-named-an-exchange-unified-messaging-partner-for-office-365-voicemail-integration/) (UM) interoperation with Exchange Online	Yes	No	No
Exchange UM interoperation with Exchange on-premises	Yes	No	No
Hybrid Lync Online and On-premises Administration
Server and cloud coexistence (split domain) on user basis (some users on-premises, some users online)	No	No	No
Splitting workloads (for example, running IM/presence/voice on-premises, and conferencing in the cloud)	No	No	No
Windows PowerShell support	Yes	No	No
Web-based user interface (Lync Server Control Panel)	Yes	No	No
Attendee/user reporting	No	No	No
Reporting (using CDR and Quality of Experience (QoE)))	Yes	No	No
Third-party API Support
Client automation APIs (client-side only)	Yes	Yes	No
Server side APIs	Yes	No	No

Read more @> http://community.office365.com/en-us/w/lync/480.aspx