A network-to-network interface, NNI device, comprising: at least one push-to-talk, PTT interface adapter ; a processor connected to the at least one PTT interface adapter; a non-transitory computer readable medium connected to the processor and having stored thereon instructions that, when executed by the processor, cause the NNI device to: receive a first PTT communication in a first PTT format through the at least one PTT interface adapter from a first PTT system ; translate the first PTT communication into a second PTT communication in one or more second PTT formats; transmit the second PTT communication through the at least one PTT interface adapter to one or more second PTT systems determine whether a conflict exists between the first PTT system and the one or more second PTT systems in roles performed with respect to PTT floor control during a PTT call; and instruct one of the first PTT system and the one or more second PTT systems to perform a role of PTT floor controller server for receiving floor control requests or transmitting group call communications, and the other to perform a role of participating PTT server for relaying all floor control requests, in response to determining that the conflict exists between the PTT systems in roles performed with respect to PTT floor control during a PTT call. at least one push-to-talk, PTT interface adapter ; a processor connected to the at least one PTT interface adapter; a non-transitory computer readable medium connected to the processor and having stored thereon instructions that, when executed by the processor, cause the NNI device to: receive a first PTT communication in a first PTT format through the at least one PTT interface adapter from a first PTT system ; translate the first PTT communication into a second PTT communication in one or more second PTT formats; transmit the second PTT communication through the at least one PTT interface adapter to one or more second PTT systems determine whether a conflict exists between the first PTT system and the one or more second PTT systems in roles performed with respect to PTT floor control during a PTT call; and instruct one of the first PTT system and the one or more second PTT systems to perform a role of PTT floor controller server for receiving floor control requests or transmitting group call communications, and the other to perform a role of participating PTT server for relaying all floor control requests, in response to determining that the conflict exists between the PTT systems in roles performed with respect to PTT floor control during a PTT call. translate the first PTT communication into a second PTT communication in one or more second PTT formats; transmit the second PTT communication through the at least one PTT interface adapter to one or more second PTT systems determine whether a conflict exists between the first PTT system and the one or more second PTT systems in roles performed with respect to PTT floor control during a PTT call; and instruct one of the first PTT system and the one or more second PTT systems to perform a role of PTT floor controller server for receiving floor control requests or transmitting group call communications, and the other to perform a role of participating PTT server for relaying all floor control requests, in response to determining that the conflict exists between the PTT systems in roles performed with respect to PTT floor control during a PTT call. <EOS>