Hi,
Ten thousand feet in the air…
Cisco FW using CPF (common packet forwarder)
https://www.tdcommons.org/cgi/viewcontent.cgi?article=4003&context=dpubs_series
CPF vs LNS (lora network protocol)
https://www.chirpstack.io/gateway-bridge/backends/basic-station/
LNS vs Semtech Basic Sation
https://www.chirpstack.io/gateway-bridge/install/config/
Did you validate the Chirpstack requirements for the Semtech BASIC station, to implements the LNS protocol for the CISCO GW ?