Aastra OpenCom 100 series, Mounting And Commissioning User Manual

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Voice over IP (VoIP)
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DHCP server uses the MAC address to select the operations software file which
matches the type of device.
3. The boot loader loads the approximately 2 MB operations software file from the
specified TFTP server. The TFTP server’s IP address and the file’s name are shown in
the display. The loaded operations software is started.
4. The operations software sends a DHCP request on the broadcast address
255.255.255.255. The VoIP system telephone now receives an IP address, network
mask and default gateway for operations from the DHCP server. Using “Option 43”,
which is reserved for this purpose, the DHCP server also provides the IP address of
the communications system and port number 8100 for registration.
5. The VoIP system telephone creates a TCP connection to the supplied IP-address/
port-number combination and sends a registration query. The OpenCom 100
checks the MAC address sent with the registration and confirms the registration
request if the VoIP system telephone is listed in the menu
Telephony: Devices:
VoIP Phones . The keep-alive time, port number (8101) for telephony signalling
and the value to use for the TOS byte are also communicated in the registration
answer.
6. The VoIP system telephone creates a second TCP connection using the signalling
port number 8101 and sends a registration.
7. Extra connections are created using the IP protocol RTP (“Realtime Transport Pro-
tocol”) for call data when a call is created. For calls between two VoIP system tele-
phones, port numbers above 8200 are used. For transmission to a Media Gateway
card, a port in the range 1024 – 1087 is used.
If you wish to operate a VoIP system telephone via a routed IP connection (for
example VPN or RAS) it may be necessary to configure an external DHCP server
accordingly. Please note the selection of the codec and keep-alive time for RAS con-
nections. This can be done by selecting the default profile
RAS in the Telephony:
Devices: VoIP Phones for the VoIP system telephone. The operations software pro-
vided via TFTP must match the type of device and communications system. You may
also need to configure BOOTP, DHCP and TFTP servers for the VoIP system telephone.
Local Configuration
In addition to automatic configuration via BOOTP/DHCP, it is possible to manually
configure an Aastra 6773ip (OpenPhone 73 IP) or an Aastra 6775ip (OpenPhone 75 IP).
This can make sense, for example, when you wish to connect a VoIP system telephone
at a distant location via router. This local configuration is saved permanently in the