3Com OfficeConnect Remote 812 manual Dhcp, Configuring the DHCP Mode

set dhcp mode [SERVER RELAY DISABLE]

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caller identity (and finds, then connects to, the recipient’s IP address). The IP address of the intended recipient is their (SIP) phone number.

By creating and storing a caller identity, a proxy server enables party A to call party B (and vice-versa), even if the recipient’s IP address (SIP phone number) is not specifically known to the caller. Additionally, through the implementation of a user name and password scheme, the proxy server provides a simple yet effective security mechanism for SIP phone callers and call recipients alike.

When a SIP phone user places a call to a conventional telephone connected to the PSTN (Public Switched Telephone Network), the call is passed to the conventional telephone via a voice gateway.

Voice Gateway

￿As the last major link in the SIP phone network infrastructure, the voice gateway forwards the IP address (SIP phone number) received from the proxy server to the telephone company’s Central Office (CO). Once received by the CO, the IP address is mapped to a conventional (non-SIP) phone number. From this point on, the phone call is processed through the telephone company network like any other non-SIP phone call originating from a conventional telephone.

For more information about 3Com SIP phone products, please see our web site at http://www.3com.com/products/sip.

Dynamic Host Configuration Protocol (DHCP) is designed to provide a centralized approach for configuration of IP addresses and parameters.

When a workstation is configured for automatic assignment of IP addresses, it broadcasts a request out on the LAN. The DHCP Server responds with an IP address for the workstation, the domain name, and the IP addresses of the default router, two DNS Servers, and two WINS Servers.

The assignment of an IP address to the workstation is for a specified period of time, referred to as the lease period. Before the lease is set to expire, the workstation will send a request to the server to extend the lease period. The server maintains a list of assigned IP addresses and the duration period of the leases. When a lease expires, the IP address can be reassigned to another workstation.

The OCR 812 can be configured to support up to 40 workstations on the local LAN. In addition, the OCR 812 can be configured to be a DHCP Relay. When enabled, the Relay will process the broadcast request from the local workstation and send it to one or two remote DHCP servers. The response from the remote DHCP servers is processed and forwarded to the local workstation.

Remember to save your configuration using the save all command before rebooting your OCR 812 so that your changes will be written to permanent FLASH memory.

The OCR 812 has three DHCP modes: Server, Relay and Disable. To configure the mode, use the following command:

DHCP 6-27

DHCP

Configuring the DHCP

Mode