Topic Last Modified: 2010-07-18
Voice over IP (VoIP) is a software-based alternative to traditional PBX-based telephony. Though the VoIP call experience is similar to the traditional telephony experience, the Microsoft Communications Server 2010 VoIP solution, Enterprise Voice, includes features that enable richer communication and collaboration. For example, your Enterprise Voice deployment can be configured to enable Microsoft Communicator "14" clients, including Microsoft Communicator “14” Phone Edition to allow users to view enhanced presence information or location information for contacts in your organization’s address book. Some Communications Server 2010 features are enabled through integration with other Communications Server 2010 workloads and with Microsoft Exchange Unified Messaging (UM).
New to Communications Server are the following Enterprise Voice enhancements for users, more effective call handling (routing and answering), and additional return on investments (ROI) for your organization:
- Users can place emergency calls that provide detailed physical
location information to the Public Safety Answering Point (PSAP)
that dispatches emergency services to the callers in distress.
- The ability for users to park a call on one phone, and then
retrieve the call from another phone.
- Routing and handling of calls placed to telephone numbers that
are valid but not assigned to any user or phone in your
- Support for users to have a second, private telephone line on
which they can be reached directly.
- The ability for a single Mediation Server to control multiple
IP-PSTN gateways. For example, gateways deployed at branch sites
can now depend on a Mediation Server deployed at the central
- New gateway topology options and the introduction of hardware
solutions—a survivable branch appliance—to address central site and
branch site Voice resiliency.
- The ability to create one or more rules that assist in
manipulating the Request URI prior to routing it to the gateway to
reduce the configuration required on the gateway to manipulate
- Flexible manipulation of the caller ID for outbound calls.
- Better scalability and high availability because calls can now
be load balanced across a pool of Mediation Servers.
- Reduced administrative overhead for hardware load balancers
with the introduction of DNS load balancing to handle SIP traffic
and media traffic for Front End pools and Director pools.
- Support for media bypass, in which media is processed by a
media termination point other than the Mediation Server. Media
bypass can help reduce latency during calls, needless translation,
the possibility of packet loss, and the number of points of
potential failure. Media bypass can also reduce the number of
Mediation Servers you need to deploy, lower bandwidth usage, and
With Communications Server, your Enterprise Voice users can also continue to do the following, as they did in previous releases:
- Place calls to and receive calls from their computers or with
USB telephones or other compatible devices.
- Place calls to and receive calls from telephones connected to a
PBX or on the PSTN.
- Place calls by clicking a contact name in Outlook or
Communicator rather than needing to remember or look up telephone
- Switch between communication modes-instant messaging,
conferencing, voice, e-mail, and other communication modes-as
- Have incoming calls ring simultaneously on all of their
communications devices, enabling users to answer wherever they have
an Internet connection and on whichever device is most
- Place calls that traverse your organization’s firewall when
users are outside or inside the firewall.
- Forward calls or delegate calls to other users or response
groups, and use other call-control features.
- Retain existing telephone numbers.
- Handle high-volume calls, with advanced features such as
consultative transfers by phone or IM, transfers with notes, and
In addition to the aforementioned productivity enhancements for users, Enterprise Voice continues to provide the following benefits for your organization:
- The ability to integrate with existing routers, gateways, PBXs,
remote call control (RCC) solutions, and telephones that are
compatible with Communications Server or to replace traditional
telephony devices with software.
- Support for USB-attached phones and other telephony devices
that support integration of the user’s phone with other
collaboration and enhanced presence features of Communications
- Use of smart, least-cost routing algorithms for calls to the
public switched telephone network (PSTN).
- Centralized administration using software tools.
- Distributed architecture that reduces bottlenecks and the
likelihood of single points of failure.
- Integration with Exchange Unified Messaging (UM) to provide
voice mail, voice messaging, e-mail messaging, call answering,
subscriber access, call notification, and auto attendant
- Connecting your on-premises voice network to one or more
service providers who offer PSTN origination, termination, and
emergency services, instead of deploying IP-PSTN gateways within
your organization’s network.
In This Section
of Enterprise Voice
- Using the
Communications Server 2010 Planning Tool to Plan for Enterprise
Basics You Must Know Before Planning
- Planning for
- Planning for
Call Management Features
High Availability for Enterprise Voice
Required for Enterprise Voice
- Planning for
Guidelines for Enterprise Voice
Process Overview for Enterprise Voice