Avaya 1600 Series Administrator's Manual page 47

Server Administration
Note:
The DHCP standard states that when a DHCP lease expires, the device should
Note:
immediately cease using its assigned IP address. If the network has problems and the
only DHCP server is centralized, the server is not accessible to the given deskphone. In
this case the deskphone is not usable until the server can be reached.
Avaya recommends, once assigned an IP address, the deskphone continues using that
address after the DHCP lease expires, until a conflict with another device is detected. As
Table 9: 1600 Series IP Deskphone Customizable System Parameters
system parameter DHCPSTD allows an administrator to specify that the deskphone will
either:
a). Comply with the DHCP standard by setting DHCPSTD to "1", or
b). Continue to use its IP address after the DHCP lease expires by setting DHCPSTD to
"0."
The latter case is the default. If the default is invoked, after the DHCP lease expires the
deskphone sends an ARP Request for its own IP address every five seconds.
The request continues either forever, or until the deskphone receives an ARP Reply.
After receiving an ARP Reply, the deskphone displays an error message, sets its IP
address to 0.0.0.0, and attempts to contact the DHCP server again.
- Option 52 - Overload Option, if desired.
If this option is received in a message, the deskphone interprets the sname and file fields in
accordance with IETF RFC 2132,
Section 9.3, listed in
- Option 53 - DHCP message type.
Value is 1 (DHCPDISCOVER) or 3 (DHCPREQUEST).
- Option 55 - Parameter Request List.
Acceptable values are:
1 (subnet mask),
3 (router IP address[es])
6 (domain name server IP address[es])
15 (domain name)
NVSSON (site-specific option number)
- Option 57 - Maximum DHCP message size.
- Option 58 - DHCP lease renew time.
If not received or if this value is greater than that for Option 51, the default value of T1
(renewal timer) is used as per IETF RFC 2131, Section 4.5, listed in
- Option 59 - DHCP lease rebind time.
If not received or if this value is greater than that for Option 51, the default value of T2
(rebinding timer) is used as per RFC 2131, Section 4.5
40 1600 Series IP Deskphone Administrator Guide
Appendix B: Related Documentation.
indicates, the
Related Documentation.