Cobalt Digital COMPASS 9223-SA Dual-Channel 3G_HD_SD MPEG-4 Encoder Unit - Manual (Page 69)

69
9223SA-OM (V2.0)
Advanced
Parameters
•
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 9223-SA 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.
•
RTP: If this box is checked, the 9223-SA will include RTP (Real Time Protocol) headers
in the output flow. If it is not checked, the transport stream will be sent over UDP/IP
without any additional headers. Note that RTP requires the use of even UDP port
numbers; when this box is checked, the user interface will enforce this restriction. The
9223-SA will not generate RTCP packets.
If the RTP box is checked, an additional control to enable SMPTE 2022 FEC may be displayed
if a FEC session is available for configuration. The 9223-SA only supports one FEC session per
Ethernet port; once FEC is enabled on a given stream, this option will not be offered for the other
streams in the same port. This is depicted below: