Issue
How many messages are buffered on a 7801?
Environment
I/NET Seven
7801x, 7803x, 7804x External or Embedded TAPs.
Cause
Even though every device in the system contains a message queue, only a few of the devices will successfully buffer the queued messages for later distribution. All controllers and Taps distribute messages out of their RS485 port even with the absence of any LAN communication. This is due to the fact that there is no requirement for an acknowledgment to be received at the generating device. The RS485 LAN is for both solicited and unsolicited message traffic. The only devices that perform extended buffering are the ones which directly communicate to polling devices such as the 7801 Taps, 7803 Taps, 7804 Taps, and all DPUs/SCUs. The MRs, ASCs, and UCs do not generate messages; messages relating to these devices are generated by the relevant MRI, MCI, etc.
Resolution
A 78-01/03/04/06 EPROM tap can buffer approximately 1000 messages. A 78-01/03/04/06 MIP tap can buffer approximately 1200 messages.
