Cisco Systems WRP400 Telephone Accessories User Manual


 
Introducing Cisco Small Business Analog Telephone Adapters
ATA Soft ware Features
ATA Administration Guide 34
1
DHCP Renewal on
Timeout
SPA2102, SPA3102, and PAP2T voice devices typically
operate in a network where a DHCP server assigns IP
addresses to the devices. Because IP addresses are a
limited resource, the DHCP server periodically renews the
device lease on the IP address. Therefore, if an ATA device
loses its IP address for any reason, or if some other device
on the network is assigned its IP address, the
communication between the SIP proxy and the device is
either severed or degraded.
Whenever an expected SIP response is not received
within a programmable amount of time after the
corresponding SIP command is sent, the DHCP Renewal
on Timeout feature automatically causes the device to
request a renewal of its IP address. If the DHCP server
returns the IP address that it originally assigned to the
device, the ATA device is presumed to be operating
correctly. If it returns a different address, the ATA device
changes its IP address to the new address provided by
the DHCP server. The ATA device then resets, and once
again sends a SIP register request for the DHCP server to
accept.
Feature Description