Lantronix EMG 8500 EMG User Guide - Page 234

10: Device Ports demand connection will be started for each, waiting for IP traffic destined for a remote network. When IP traffic needs to be sent, the EMG unit dials the appropriate Dial-out Number for the site, and if the remote peer requests PAP or CHAP authentication, provides the Dial-out Login and Dial-out Password as authentication tokens. Once authenticated, a PPP session will be established using either negotiated IP addresses or specific IP addresses (determined by the Negotiate IP Address setting). The PPP connection will stay active until no IP traffic is sent for Modem Timeout seconds. Once the timeout has expired, the PPP connection will be terminated and will not be reestablished for at least Restart Delay seconds. CBCP Server and CBCP Client Callback Control Protocol (CBCP) is a PPP option that negotiates the use of callback where the server, after authenticating the client, terminates the connection and calls the client back at a phone number that is determined by the CBCP handshake. For more information on CBCP, see http://technet.microsoft.com/en-us/library/cc957979.aspx. CBCP is used primarily by Microsoft PPP peers. CBCP supports two options for determining the number to dial on callback: the client can specify a user-defined number for the server to dial on callback, or the client can request the server use an administrator-defined number to dial on callback. Optionally, some servers may also allow "no callback" as an option. CBCP Server The EMG waits for a client to call the EMG unit, establishes a PPP connection, authenticates the user, and negotiates a dial-back number with the client using CBCP. If the EMG is able to determine a dial-back number to use, it hangs up and calls the dial-back number. When a call is received, a PPP connection is established, and the user will be authenticated via PAP or CHAP (configured with the Authentication setting). For PAP, the Local/Remote list will be used to authenticate the login and password sent by the PPP peer. For CHAP, the CHAP Handshake Host/User Name and Secret/User Password will be used to authenticate CHAP Challenge response sent by the PPP peer. If the remote peer requests PAP or CHAP authentication from the EMG unit, the Remote/Dial-out Login and Remote/Dial-out Password will be provided as authentication tokens. Once authenticated, the CBCP handshake with the client determines the number to use for dial-back. The EMG unit will present the client with the available options: if the authenticated user is a Local/Remote User with Allow Dial-back enabled and a Dial-back Number defined, the administrator-defined option is allowed; if this is not the case, the user-defined number is allowed. Additionally, if CBCP Server Allow No Callback is enabled, the client can also select no callback (the PPP connection established at dial-in will remain up). The client will select from the available callback options. If the EMG unit can determine a dial-back number to use, it will hang up and wait Dial-back Delay seconds before initiating the dial-back (if the dial-back fails, the EMG will try Dial-back Retries times to dial-back). The EMG unit will call back the previously authenticated remote peer, and if the remote peer requests PAP or CHAP authentication, provide the Remote/Dial-out Login and Remote/Dial-out Password as authentication tokens. Once authenticated, a PPP session will be established using either negotiated IP addresses or specific IP addresses (determined by the Negotiate IP Address setting). CBCP Client The EMG unit will dial out to a CBCP server, establish a PPP connection, negotiate a callback number with the server using CBCP, terminate the connection, and wait for the server to call back. The EMG unit dials the Dial-out Number, and if the remote peer requests PAP or CHAP authentication, provides the Remote/Dial-out Login and Remote/Dial-out Password as authentication tokens. Once authenticated, the CBCP handshake with the server determines the EMG™ Edge Management Gateway User Guide 234