Video switch detection, Tos switch detection, Video switch detection -34 – Comtech EF Data CDM-570/570L Vipersat User Manual

Page 70: Tos switch detection -34

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Vipersat Configuration

3-34

Vipersat CDM-570/570L User Guide

Entering O at the command prompt toggles the Voice Switch Detection

command for the CDM-570/570L between Enabled and Disabled. When

enabled, a voice data-stream will be detected, causing the CDM-570/570L to

send a switch request to the VMS to switch from STDMA to SCPC mode.

Video Switch Detection

This menu item appears for Remote modems only.
Video Switch Detection is one of the Application switching commands that

provides for a dedicated SCPC connection when an H.323 video call is made

over the satellite network.
Entering I at the command prompt toggles the Video Switch Detection

command for the CDM-570/570L between Enabled and Disabled. When

enabled, a video data-stream will be detected, causing the CDM-570/570L to

send a switch request to the VMS to switch from STDMA to SCPC mode.

ToS Switch Detection

This menu item appears for Remote modems only.
One of the four automatic switching functions that the Vipersat CDM-570/570L

is able to perform is ToS (Type of Service) Switching. ToS is defined by an

eight bit field within an IP packet header that is used to set up per-hop-based

QoS rules for prioritizing packets. Because the ToS field remains untouched by

most encryption methods, ToS switching provides an alternative means of

SCPC switching when encryption prevents the detection of SIP and H.323

protocols.
ToS detection occurs in the Remote modem which only looks at traffic that is

passed in the LAN-to-SAT (Remote to Hub) direction. Once the ToS Switch

Detection feature is enabled, the Remote modem will send an ASR to the VMS

when a packet stamped with the ToS is detected. The ASR contains the destina-

tion IP address of the ToS stamped packet, the desired SCPC rate, and the VMS

Switch Type (policy #). If available hardware and bandwidth exist, the VMS

will establish the SCPC carrier automatically.
Entering T at the command prompt in figure 3-41 toggles the TOS Switch

Detection command for the CDM-570/570L between Enabled and Disabled.

When enabling ToS switching, the ToS switching control parameters must be

defined as described in the section “ToS Switching Parameters” on page 3-45.
Applying a ToS value to an application (VoIP, IPVC, or priority data) through

either preservation or classification packet stamping allows the Vipersat switch-

ing system to function in an encrypted network. Normally in a non-encrypted

Vipersat network, packets are classified by the Remote CDM-570/570L using

protocol classification detection and the results are forwarded to VMS via

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