Aastra M720, Руководство по установке

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AMT/PTD/TR/0001/3/7/EN Installation Manual Digital sets - IP Sets - SIP Sets
Page 16-14 05/2008 Appendix
offered, the subnet mask, the lease duration and the IP address of the DHCP server that is making
the offer.
16.3.1.3 IP lease selection
When the client i7xx set receives an IP lease offer, it must inform all the other DHCP servers that it
has accepted an offer. To do this, the client issues a DHCP_REQUEST message containing the IP
address of the server that issued the offer.
16.3.1.4 IP lease acknowledgment
When the DHCP server receives the DHCP_REQUEST message from the client, it initialises the
final phase of the configuration process. This acknowledgment phase involves sending a
DHCP_ACK packet to the client. This packet specifies the lease duration and any other
configuration information that the client i7xx set may have requested.
At this stage, the TCP/IP configuration process is finished.
16.3.2 Full DHCP with VLANs and DHCP servers
In full DHCP, in a multiple VLAN environment with several DHCP servers (data and telephony), the
starting procedure is as follows:
• The set negotiates its DHCP lease using an untagged IEEE 802.3 Ethernet frame format.
• As the DHCP server located in the data VLAN sends a lease proposal containing the IP
address parameters, subnet mask, IP address of the "default gateway" and additional
parameters, IP address of the Call Server, IP address and port number of the downloading
server, activation of IEEE 802.1Q tagging, VLAN number and priority to be used by the set.
If IEEE 802.1 mode is not enabled by the DHCP lease (VLAN = 0), the set continues its connection
process and continues to operate in IEEE 802.3 mode.
If IEEE 802.1 mode is enabled (VLAN = 1), the set sends a release request for this lease to the first
DHCP server (VLAN data) by maintaining the VLAN number (telephony VLAN) to be used.
• The set then switches to IEEE 802.1Q/P mode by tagging the VLAN part and priority with the
information received from the first DHCP server without rebooting.
i7XX
DHCP
server
DHCP Discover
DHCP Offer
DHCP Request
DHCP Ack