Configuring Port Ranges for Your Conferencing, Application, and Mediation Servers

Topic Last Modified: 2014-02-05

In order to implement Quality of Service, you should configure identical port ranges for audio, video, and application sharing on your Conferencing, Application, and Mediation servers; furthermore, those port ranges must not overlap in any way. To use a simple example, suppose you use ports 10000 through 10999 for video on your Conferencing servers. That means that you must also reserve ports 10000 through 10999 for video on your Application and Mediation servers. If you do not, QoS will not work as expected.

Similarly, suppose you reserve ports 10000 through 10999 for video, but then reserve ports 10500 through 11999 for audio. This can create problems for Quality of Service, because the port ranges overlap. With QoS, each modality must have a unique set of ports: if you use ports 10000 through 10999 for video, then you'll have to use a different range (for example, 11000 through 11999 for audio).

By default, audio and video port ranges do not overlap in Microsoft Lync Server 2013; however, the port ranges assigned to application sharing overlap with both the audio and video port ranges. (Which, in turn, means that none of these ranges are unique.) You can verify the existing port ranges for your Conferencing, Application, and Mediation servers by running the following three commands from within the Lync Server 2013 Management Shell:

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Get-CsService -ConferencingServer \| Select-Object Identity, AudioPortStart, AudioPortCount, VideoPortStart, VideoPortCount, AppSharingPortStart, AppSharingPortCount Get-CsService -ApplicationServer \| Select-Object Identity, AudioPortStart, AudioPortCount Get-CsService -MediationServer \| Select-Object Identity, AudioPortStart, AudioPortCount

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Get-CsService -ConferencingServer | Select-Object Identity, AudioPortStart, AudioPortCount, VideoPortStart, VideoPortCount, AppSharingPortStart, AppSharingPortCount

Get-CsService -ApplicationServer | Select-Object Identity, AudioPortStart, AudioPortCount

Get-CsService -MediationServer | Select-Object Identity, AudioPortStart, AudioPortCount

Warning:
As you can see in the preceding commands, each port type – audio, video, and application sharing – is assigned two separate property values: the port start and the port count. The port start indicates the first port used for that modality; for example, if the audio port start is equal to 50000 that means that the first port used for audio traffic is port 50000. If the audio port count is 2 (which is not a valid value, but is used here for illustration purposes) that means that only 2 ports are allocated for audio. If the first port is port 50000 and there are a total of two ports, that means the second port must be port 50001 (port ranges have to be contiguous). As a result, the port range for audio would be ports 50000 through 50001, inclusive. Note, too that Application server and Mediation server only support QoS for audio; you do not need to change video or application sharing ports in your Application servers or Mediation servers.

Warning:

As you can see in the preceding commands, each port type – audio, video, and application sharing – is assigned two separate property values: the port start and the port count. The port start indicates the first port used for that modality; for example, if the audio port start is equal to 50000 that means that the first port used for audio traffic is port 50000. If the audio port count is 2 (which is not a valid value, but is used here for illustration purposes) that means that only 2 ports are allocated for audio. If the first port is port 50000 and there are a total of two ports, that means the second port must be port 50001 (port ranges have to be contiguous). As a result, the port range for audio would be ports 50000 through 50001, inclusive.

Note, too that Application server and Mediation server only support QoS for audio; you do not need to change video or application sharing ports in your Application servers or Mediation servers.

If you run the preceding three commands you'll see that that the default port values for Lync Server 2013 are configured like this:

Property	Conferencing Server	Application Server	Mediation Server
AudioPortStart	49152	49152	49152
AudioPortCount	8348	8348	8348
VideoPortStart	57501	--	--
VideoPortCount	8034	--	--
ApplicationSharingPortStart	49152	--	--
ApplicationSharingPortCount	16383	--	--

As noted previously, when configuring Lync Server ports for QoS, you should ensure that: 1) audio port settings are identical across yours Conferencing, Application, and Mediation servers; and, 2) port ranges do not overlap. If you look closely at the preceding table, you will see that the port ranges are identical across the three server types. For example, the starting audio port is set to port 49152 on each server type, and the total number of ports reserved for audio in each server is also identical: 8348. However, the port ranges overlap: audio ports start at port 49152, but so do the ports set aside for application sharing. In order to make optimal use of Quality of Service, application sharing should be reconfigured to use a unique port range. For example, you could configure application sharing to start at port 40803 and to use 8348 ports. (Why 8348 ports? If you add those values together -- 40803 + 8348 -- that means that application sharing will use ports 40803 through port 49151. Because audio ports do not begin until port 49152, you will no longer have any overlapping port ranges.)

After you have selected the new port range for application sharing you can make your change by using the Set-CsConferencingServer cmdlet. This change does not need to be made on your Application servers or on your Mediation servers, because these servers do not handle application sharing traffic. You only need to change port values on these servers if you decide to reassign the ports used for audio traffic.

To modify the port values for application sharing on a single Conferencing server run a command similar to this from within the Lync Server Management Shell:

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Set-CsConferenceServer -Identity ConferencingServer:atl-cs-001.litwareinc.com -AppSharingPortStart 40803 -AppSharingPortCount 8348

If you want to make these changes on all your Conferencing servers you can run this command instead:

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Get-CsService -ConferencingServer \| ForEach-Object {Set-CsConferenceServer -Identity $_.Identity -AppSharingPortStart 40803 -AppSharingPortCount 8348}

After changing port settings you should stop and then restart each service affected by the changes.

It is not mandatory that your Conferencing servers, Application servers, and Mediation servers share the exact same port range; the only true requirement is that you set aside unique port ranges on all your servers. However, administration will typically be easier if you use the same set of ports on all your servers.