A method of performing maintenance on a network access server having associated channels carrying incoming digital or analog traffic determines whether maintenance is needed on a network access server and then communicating a busy condition of any unused associated channel from the network access server to the service request switch. Used channels are monitored for existing calls and when the used channel becomes substantially unused as indicated by defined digital and analog signaling protocol a busy condition is communicated from the network access server to the service request switch. An unused channel may be determined by usage falling below a predetermined threshold. Any remaining, existing calls are migrated to other network access servers. A signal is then sent to indicate that maintenance on the network access server can be performed and new requests arriving during a busy condition of the network access server are routed to another network access server.