Specifications

MBG Engineering Guidelines, Release 8.0
congestion.
If the remote VoIP devices are only using voice then the bandwidth purchased for the EF queue must be large
enough to accommodate the total number of concurrent voice streams passing through the MBG from Internet to
managed WAN. However, if the remote VoIP devices will also be using video in this example, then the bandwidth
purchased for the EF queue must account for both voice and video, keeping in mind that a video call requires 10
to 20 times more bandwidth than a compressed audio call even when devices are configured with the lowest
bandwidth settings. Refer to section 12.3 Determine Bandwidth Requirements for guidance on calculating
required bandwidth.
Alternatively, if the cost is prohibitive for provisioning enough EF queue bandwidth to support both voice and
video needed for the deployment, then MBG should not be configured to insert an EF value (46 decimal) for
voice/video packets. The reason for this is to prevent video passing through the MBG from impacting voice on a
managed WAN where EF bandwidth has only been provisioned for voice. A future release of MBG will support
configuring different values for voice and video to address this scenario.
Recommended settings when enough EF queue bandwidth has been provisioned to support both voice and
video:
• voice/video : 46 decimal (Expedited Forwarding)
• signaling : 24 decimal (Class Selector 3)
Recommended settings when enough EF queue bandwidth has been provisioned to support voice only:
• voice/video : 34 decimal (Assured Forwarding 41)
• signaling : 24 decimal (Class Selector 3)
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