Kenwood TS-990S Setting Manual page 32

(Supplement): FAQ: Explaining the Internet "Cannot operate transceiver"
As shown in Fig. 1, even though only one broadband router (BBR) is visible on the
network, in reality there are two. (Duplex router phenomenon.)
There are multiple modems with built-in BBR functions, so when connecting such
a modem as described above, there must not be two BBR paths connecting the PC
to the Internet.
Consequently, even if the open port has been set for one BBR only, the required
KNS packets will not flow. For this reason, either set the required KNS port to open
for both BBRs, or stop one BBR function, and set the network so that there is only
one BBR on the network.
As shown in Fig. 2, the case where a telephone is connected directly to a modem,
in most models the modem has a built-in BBR function. In such cases, stopping
the function of the BBR built into the modem stops the VoIP telephone functions
connected to the modem, so VoIP telephony use is disabled.
To prevent the VoIP telephone functions from stopping, stop the functions of the
BBR connected to the front of the PC, and set the port required by KNS to open in
the BBR built into the modem.
Caution:
Change any settings such as open BBR ports at your own risk.
If you do not have confidence in the settings, we recommend you stop using the
system.
Fig. 1
Fig. 2
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