Cobalt Co9992-4ENC-4K-HEVC Software-Defined Broadcast Encoder - Manual (Page 90)

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If the Advanced View is selected, four more parameters are available for configuration:

TOS: This parameter allows the configuration of the Type-Of-Service (TOS) byte in the
IP header (also known as the Differentiated Services – DS – field). Valid values are
between 0 and 255. Configuring this is only useful if the downstream router is
configured to honor the field.

TTL: This parameter allows the configuration of the Time-To-Live (TTL) byte in the IP
header. Valid values are between 0 and 255. If not explicitly configured, it defaults to
128. This field controls how many hops the packet can traverse before it is dropped by a
router. The default value of 128 is suitable for virtually all applications.

DF Bit: This parameter allows the configuration of the Do-not-Fragment (DF) bit in the
IP header. The 9992-ENC will never produce fragmented packets, and with the UDP
payload set to 7 transport packets, the IP packets are guaranteed to fit inside the Ethernet
MTU. This control is provided for compatibility with legacy switches/routers. Some
legacy equipment may exhibit performance problems if this bit is not set. This is not an
issue with current network equipment.