This section describes the bandwidth requirements for 50, 250, 800 and 2000 user systems. Meeting the bandwidth requirements
outlined in the section will provide a quality end user experience for your users who host and attend Webex meetings, and
helps ensure that your network can support the traffic demands from the web sharing, audio, and video.
Bandwidth for End User Sessions
It is important to estimate the network bandwidth to support the traffic demands of video, audio, and web sharing for the
size of your user system. The bandwidth requirements for this product are fundamentally the same as for Cisco Webex cloud
services. If you wish to optimize your network provisioning, Cisco Webex cloud services bandwidth usage is presented in the
Webex Network Bandwidth White Paper.
The information in
the following table shows the expected bandwidth for video, audio and web
Webex Meeting Component
Aggregate End User Session Bandwidth
(360p + 6 thumbnails)
value assumes you flip a slide every 30 seconds.)
Total maximum bandwidth
Although 2.2 Mb/s
is the maximum expected bandwidth for a single user connection, Cisco
recommends using the maximum expected bandwidth of 1.5 Mb/s when calculating
bandwidth requirements. Because only one-half of the maximum number of users
can employ video, audio, and web sharing while the remaining users should use
only audio and web sharing, this yields an average bandwidth of approximately
1.5 Mb/s per user connection.
If you refer to the Webex Network Bandwidth White Paper, you will notice that the bandwidth values in the preceding table are based on worst-case traffic conditions. Average bandwidth
utilization is much smaller, but Cisco recommends using worst case numbers for the following reasons:
worst case numbers for your calculation should help you provide the needed
bandwidth to prevent a degraded user experience as a result of heavy usage.
The Cisco Webex Meetings Server sends the same data simultaneously to all the participants in a meeting. When a Webex host
flips a page on a presentation, an image of that page (possibly comprising several megabytes) is sent separately to each endpoint,
simultaneously, and as quickly as possible.
Use the following
process to determine the necessary bandwidth on various network paths.
- Determine the averaged
bandwidth for a user session using the table provided in the preceding section.
maximum number of users you expect to connect simultaneously over that link.
total bandwidth by the maximum number of users.
If you expect
a maximum of 100 users to connect concurrently from the Internet, you will
probably need 1.5 Mb/s x 100 = 150 Mb/s of available bandwidth on your ISP
connection and through your external firewall to the Internet Reverse Proxy.
For details about Internet Reverse Proxy, see
Network Considerations for the Internet Reverse Proxy
have a 2000 user system with all connections going through the Internet Reverse
Proxy. In this scenario, you need to assume traffic for all 2000 users will
connect to the Internet Reverse Proxy, and then from the Internet Reverse Proxy
to the internal virtual machines. The aggregate bandwidth coming into the
Internet Reverse Proxy from other parts of the network will be 2000 x 1.5 Mb/s
= 3 Gb/s. For details about non-split-horizon, see
Non-Split-Horizon Network Topology.
The same 3
Gb/s of traffic passes inbound and outbound through the Internet Reverse Proxy,
requiring the NIC on the Internet Reverse Proxy to handle 6 Gb/s of user
traffic. See the next section for more information about bandwidth requirements
for the NIC on the Internet Reverse Proxy.
have 2000 user system in a split-horizon DNS deployment. In this scenario, your
Internet users will connect to the Internet Reverse Proxy while intranet users
connect directly to the internal virtual machines. Assume ten percent of your
users connect to a meeting using the Internet versus 90 percent of users
connect to their meetings through the Intranet. The result is the aggregate
bandwidth coming into the Internet Reverse Proxy will now be approximately 300
Mb/s (10 percent of 2000 users times 1.5 Mb/s equals 300 Mb/s). If that same
300 Mb/s of traffic passes from the Internet Reverse Proxy, the NIC on the
Internet Reverse Proxy may be required to handle 600 Mb/s of user traffic. This
is a dramatically lower bandwidth requirement than with a non-split-horizon DNS
deployment described in the previous scenario. The reduction in network traffic
has direct bearing on the recommendations for NIC or switch interface speed
(see next section) which can result in you being able to deploy less expensive
1 Gb/s NICs on the Cisco UCS Server for the Internet Reverse Proxy or 1 Gigabit
Ethernet Switch Infrastructure in DMZ network. For more details about
Split-Horizon Network Topology.
You may be
required to deploy 1 Gigabit Ethernet NICs configured for NIC Teaming if the
Internet Reverse Proxy usage is marginally close to the 1000 Mb/s threshold.
NIC Teaming for Bandwidth Aggregation
for more details.
Bandwidth on Cisco Webex Meetings Server Network Interfaces
interfaces between your switching architecture and your system, we recommend
provisioning your interface NICs to the maximum speeds shown in the following
table. These speeds apply to the connectivity between the Cisco UCS Servers and
ports on head-end switches in your local switching infrastructure only. These
are the recommended speeds needed to support worst-case traffic requirements.
Switch Interface Speed
See the next
section, "Bandwidth Considerations for Split-Horizon DNS Deployments," for more
information about using 1 Gb/s NICs and Ethernet switches for a split-horizon
Assumptions for NIC Speed
end-user session bandwidth (1.5 Mb/s) was used to calculate the NIC speeds
shown in the preceding table.
inter-virtual machine control traffic must be free of congestion. This
especially applies to 2000 user systems and any system provisioned for high
availability. Severe congestion on virtual machine links can result in system
instability and consequent interruption of service.
connections to NAS storage, used for recording and database backup, must not be
overhead and implementation inefficiencies result in usable link bandwidth that
is significantly less than the 1 Gb/s or 10 Gb/s speed labels.
If a large
percentage of your traffic will hit the Internet Reverse Proxy when users log
in to meetings, you need to remember that every user connection passes twice
through the NIC on the Internet Reverse Proxy (inbound and outbound). Using the
2000 user system as an example, this means the NIC on the Internet Reverse
Proxy may be required to handle 6 Gb/s of user traffic (2000 users times 1.5
Mb/s equals 3 Gb/s, times two for inbound and outbound traffic equals 6 Gb/s).
we ask that the local connections be no more than 60 percent used for end user
media traffic, allowing the remaining 40 percent to be available for other
traffic, unusual traffic bursts, and network overhead. Using the 800 user
system as an example, we estimate the end user traffic at 1.2 Gb/s for the
Admin and Media virtual machines and 2.4 Gb/s for the Internet Reverse Proxy
virtual machine. Applying the 60 percent rule, we want the NIC to be capable of
handling 2 Gb/s for the Admin and Media virtual machines (1.2 Gb/s estimated
user traffic for the Admin and Media virtual machines divided by 60 percent
estimated normal bandwidth consumption equals 2.0 Gb/s) and 4 Gb/s for the
Internet Reverse Proxy virtual machine.
The NIC speeds
shown in the preceding table do not account for bandwidth used for accessing
SAN storage. If Fibre Channel over Ethernet (FCoE) is used for a SAN
connection, it should be provisioned to use an independent network interface.
Considerations for Split-Horizon DNS Deployments
split-horizon DNS deployment, some of your users will be logging in to meetings
from the Internet and that traffic will hit the Internet Reverse Proxy, while
the majority of users who are on the internal network will be logging into
meetings without hitting the Internet Reverse Proxy. With a split-horizon DNS
deployment, if you speed up your network and segment your traffic so that most
of your traffic stays within the internal network (as opposed to hitting the
Internet Reverse Proxy), you can potentially use NIC Teaming and provision a
lower-end NIC (1 Gb/s NIC) on the Internet Reverse Proxy and provision the
switching infrastructure between the Internet Reverse Proxy and the Internet to
be 1 Gb/s, or at least lower than the recommended 10 Gb/s, for a 2000 user
For example, if a company has 100 users who want to access a 2000 port user system from the Internet concurrently, you would
need a bandwidth of 150 Mb/s (1.5 Mb/s aggregate user session bandwidth * 100 users = 150 Mb/s). This implies that a network
infrastructure from the DMZ network to the Internet Reverse Proxy can be 1 Gb/s Ethernet switches, and the Ethernet NIC interface
on the Internet Reverse Proxy can be 1 Gb/s, as opposed to the stated 10 Gb/s interface requirement. Even when you factor
in that the Internet Reverse Proxy sees double the traffic (meaning its NIC would have to handle 300 Mb/s of user traffic),
applying the 60 percent rule (explained in the "Bandwidth on Cisco Webex Meetings Server Network Interfaces" section) translates
to 500 Mb/s. A 1 Gb/s link is still sufficient, but it would not be sufficient if we assumed 250 users instead of 100 users.
of bandwidth is only applicable for the NIC on the Internet Reverse Proxy in a
split-horizon DNS deployments.
non-split-horizon DNS deployments, you must deploy 10 Gb/s Ethernet switches
and Ethernet NIC interfaces on the Internet Reverse Proxy.