Avaya CS 1000, Основы

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server. The DAP then downloads the configuration files from the TFTP server. The TFTP
server often runs on the DAP controller or manager PC.
• The DHCP server (optional) sends the address of the DNS server to the DAP. The DAP
does not support Domain Name Resolution.
• The DAP controller or manager requires a fixed IP address. The DAPs retrieve this fixed
IP address from the configuration file that the DAP loads from the TFTP server.
• The IP address of the PABX is reachable either through a router or directly. The PABX is
sometimes referred to as Gatekeeper or SIP proxy, depending on the type of PABX that
is used.
To facilitate network management, Avaya recommends that fixed IP addresses are also
assigned by the DHCP server. Ensure that the DHCP server has the hardware MAC addresses
of all servers to issue the proper (fixed) IP addresses to each individual server.
The DAP IP address can be stored in flash memory. If the IP address is stored, the DHCP
server is needed only for the first startup. Then an IP address is assigned to the DAP.
Dynamic IP network addresses
Network stations, which are not servers (PC workstations and DAPs), can use dynamic IP
addresses assigned by DHCP. For dynamic IP addresses, you need not specify the MAC
addresses of all the network stations in the DHCP server.
Ensure that you configure the DHCP server to assign IP addresses from a specific range to
unknown MAC addresses. However, unknown LAN stations have valid IP addresses, which
can be a minor network security issue. To solve this, use the Vendor Class Identification (VCI)
in the DHCP server. The DHCP server issues IP addresses only to devices that have the DAP
VCI. Ensure that the DHCP server can make a distinction in VCIs. The DAP VCI is D(ECT)AP
49.
Each DAP in a SIP DECT system is assigned a dynamic IP addresses by the DHCP server.
You can configure the DAPs to store the IP address in flash memory, so the DHCP server is
required only during the initial configuration of the system.
Multicast addresses
SIP DECT uses Multicast addresses for the following functions:
• Communication between the SIP DECT network components to locate or address a
handset. If a handset must be reached, the request must simultaneously go to all DAPs.
For example, if you use the page function during an incoming call, a single multicast
message is sent to all DAPs to find the DAP for your handset quickly and efficiently.
• Seamless handover from one DAP to the other If inter-cell handover is necessary, the
media path must be redirected from the existing DAP to another DAP. The handset always
initiates a handover. The handset sends request to another DAP (not the DAP with the
Components of SIP DECT systems
SIP DECT Fundamentals October 2012 25