Network Technologies ASI-IP-GTW User Manual

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ASI-IP-GTW User's Manual 
 
 Page 
52 
3.7.5 Advanced Tab 
 
 
Figure 24 Advanced Tab 
On the advanced tab it is possible to control and inspect the status of 
the buffer regulator for a port. 
 
Pref. Init. Rate Mode: This parameter is used to select the preferred 
algorithm to use to find an initial bitrate for a received data stream.  
o  PCR:
 The default mode is ‘PCR’, in which a number of consecutive 
TS packets on the first PCR PID encountered are used to calculate 
the bitrate. If no PCR PID is found, COARSE mode is 
automatically used. 
o  MIP:
 This mode may be used for signals that do not contain any 
PCR PIDs, but do have a DVB MIP PID (PID 21) used in Single 
Frequency Networks. In MIP mode, two consecutive MIP packets 
are used to estimate the bitrate. If no MIP PID is found, COARSE 
mode is automatically used. 
o  COARSE:
 In this mode, a simple 2 second measurement is used to 
estimate the bitrate. This method is sensitive to network jitter and 
does not give as good results as PCR and MIP mode. 
o  VBR:
 In this mode, the unit attempts to transmit data at the rate 
entered in the Max bitrate input. If the incoming rate is lower than 
this, the unit will either pad with idle bytes (resulting in a VBR 
output stream) or with NULL packets, depending on whether the 
“Pad with NULL packets” checkbox is checked. In this mode, no 
PCR adjustment is performed.