HP Survivable Branch Communication zl Module powered by Microsoft Lync Planning and Design Guide 2011-02

2-5
Design Considerations
Planning Call Capacity
Considerations for Local Peer-to-Peer Calls
The SBM imposes no special limit on local peer-to-peer calls (calls between
Lync users at the same branch). Each of the 1000 users can make such a call
simultaneously. Providing the 25 to 90 Kbps required for a typical call should
not cause a problem for the LAN. However, other features such as video
conferencing and file sharing add to the bandwidth requirements.
The table displays Microsoft’s recommendations for provisioning the Lync
endpoints’ connections. Note that an application such as video conferencing
would require audio traffic, video traffic, and perhaps a feature such as
RoundTable. You would need to total the required bandwidth for each com-
ponent.
Table 2-2. Estimate Bandwidth Requirements for a Lync Endpoint’s Connection
Note Providing adequate QoS for the calls involves more planning. See “Ensure QoS
for VoIP calls within the Network Infrastructure” on page 2-19.
Considerations for Local PSTN Calls and Planning Your
Telephony Cards
For local PSTN calls, you are limited to the number of channels in the SBM’s
PSTN lines (one call per channel). The SBM provides two PCIe slots that
support a variety of telephony options. You must purchase telephony cards
that meet your capacity requirements.
Feature Minimum Bandwidth Typical Bandwidth Maximum
Bandwidth
Audio 40 Kbps 95 Kbps 160 Kbps
Video
CIF
50 Kbps 210 Kbps 250 Kbps
Video
VGA
350 Kbps 500 Kbps 600 Kbps
Video
High definition
800 Kbps 1.2 Mbps 1.5 Mbps
RoundTable
50 Kbps 280 Kbps 350 Kbps
Web conferencing
(PSOM)
20 Kbps 200 Kbps 500 Kbps
File transfer
20 Kbps 200 Kbps 200 Kbps
Application sharing
256 Kbps 1 Mbps 3.5 Mbps