Comtech EF Data VMS v3.12.x Vipersat - Manual (Page 473)

Appendix E - Automatic Switching E-17
MN/22156, rev 12 Application Switching
Each application type will have been assigned a bandwidth allocation when the
policy for the Remote is established. The voice application, for example, might
have had the bandwidth set in the policy to handle three simultaneous voice
connections. When a VoIP protocol is detected in the H.225 signaling protocol,
the modem/router requests the VMS to switch the bandwidth to accommodate
three voice circuits.
The same process applies if the protocol detected is Video.
When both VoIP and Video are requested, the bandwidth required for the Video
is used and the VoIP, which has priority, shares the SCPC with the Video.
Once the VMS receives the request to switch, it determines if there is a free
demodulator and if there is bandwidth space available to handle the requested
application. If the resources are available, the VMS then performs the switch.
Applications are streaming data. The Remote looks at the streaming data flow
until it sees a break in the data exceeding 10 seconds. Once a break is detected
the modem/router presumes that the application is terminated (or has malfunc-
tioned), drops the carrier, and makes the bandwidth resources available for
another service.