About This Article

The following instructions are necessarily at a high level, because the network configuration may be very different for each enterprise customer. This information is meant to be passed to your IT department or the people responsible for your business network.


In this article, you will do the following:

  • Ensure you have adequate bandwidth from your users' computers to the network device (LAN or WAN) and then adequate bandwidth on the WAN side.
  • Configure your firewall(s) to ensure that MaX UC Desktop can communicate with TCT's servers.
  • Configure your network to correctly prioritize VoIP signaling, voice and video traffic.


Configure Bandwidth Requirements

You must ensure that you have adequate bandwidth for the number and types of calls that you are expecting.

  1. For audio calls, the amount of bandwidth you need depends on the codec you are using. You should allow 100kbps (in each direction) for every call.
    • Therefore, if you expect a maximum of 10 concurrent calls, you should assign 1Mbps of bandwidth for voice calls alone, and then ensure you have adequate bandwidth on top of that for other traffic (VPN, web, file transfer) which shares the same connection.
  2. For video calls, the bandwidth requirement varies hugely depending on resolution, ranging from 500Kbps (low definition) up to 8000Kbps (HD), again in each direction per concurrent video call.
  3. For Meeting, the MaX UC Desktop client requires the following bandwidth to utilize Meeting.
    • Audio stream: 60-80 Kbits/s
    • Video stream: up to 2 Mbits/s for HD
    • Screen sharing: 200 Kbits/s


Configure your Firewall

You must ensure that you have the correct ports open on your firewall to ensure that MaX UC Desktop can communicate with TCT' servers.


By default many firewalls will allow communication from the internal LAN side meaning that no configuration is required here. However, if your firewall requires specific configuration, you must ensure that it is not blocking traffic.


You must ensure that standard ports, notably 80 for HTTP and 443 for HTTPS, are open. In particular, MaX UC Desktop requires access to commpapps.metaswitch.com, using either HTTP or HTTPS (TCP). This is the CommPortal Server that provides the specific configuration for each customer and is used for updating the app and providing the branding. This server is hosted on Google App Engine, so does not have a static IP address.


The following table defines the external IP addresses and ports that the MaX UC Desktop client also needs to be able to reach through your firewall.


Protocol/ServiceTransportExternal IP Address and PortsNotes
SIP/TLSUDP72.21.78.240
208.77.63.131
208.93.135.178
The signaling IP address and port of the TCT Session Border Controller.
RTPUDP72.21.78.240
208.77.63.131
208.93.135.178
The media IP address and port range of the TCT Session Border Controller.


Configure your Quality of Service Settings (Simple Network)

For optimal audio quality, you must ensure that your network is set up to correctly prioritize VoIP signaling, voice and video traffic.


The steps you need to take depend on the configuration of your network. If you have a very complex set up, then you may need to contact your equipment vendor for advice.


If you have a simple network, you will typically only need to do the following:

  • If any MaX UC Desktop user will access your network via a wireless Access Point (AP), ensure that WMM (Wireless Multimedia extensions) support is available and enabled on any such access points.
  • Use Quality of Service (QoS) on the WAN/Internet router to prioritize all traffic to and from the TCT SBC IP addresses.


Configure your Quality of Service Settings (Complex Network)

If you have a more complex network then you may need to carry out further configuration to ensure optimal audio quality.

  1. Ensure the correct QoS information is signaled on traffic originated by users' computers.
    • The BluePrint Support team can configure the QoS values that MaX UC Desktop will signal in MaX UC Desktop.
    • However, if you are in an Active Directory domain, Windows will override these values. Instead you will need to configure a QoS group policy that looks for any packets coming out of communicator.exe and marks them appropriately (typically with DSCP 24 if they are going to ports 5060-5070 (signalling) or 46 if they are UDP on any port above 8000 (media)).
  2. Configure all your network equipment to correctly prioritize traffic based on the IP header DSCP markings.
    • Signalling traffic should be guaranteed delivery at a higher priority than regular traffic.
    • Media traffic should be expedited delivery at the highest priority.
  3. You may also need to configure your equipment to re-write the Ethernet header COS values based on the IP header DSCP values - if you don't then most managed switches will re-write DSCP marking based on COS (and COS will typically be zero or incorrect on packets originated from a computer).


Set DSCP Marking for Domain-Joined Windows Computers

You must set group policies if you want to do DSCP marking on domain-joined Windows machines.


You can either allow all apps to mark traffic as they wish, or you can create policy conditions and set these to match your individual network set-up for MaX UC Desktop. The simplest way to do this is to match on the application maxuc.exe, as illustrated below.


Policy NameDSCP ValueThrottle Rate (KBps)Policy Conditions
MaX UC - AlamedaPBX Signalling24Not Specified

Protocol: TCP and UDP

Application: maxuc.exe

Source IP: Any

Destination IP: 72.5.9.120/32

Source Port: Any

Destination Port: 5060:5070

MaX UC - EMEAPBX Signalling24Not Specified

Protocol: TCP and UDP


Application: maxuc.exe


Source IP: Any


Destination IP: 192.91.191.8/32


Source Port: Any


Destination Port: 5060:5070