Snom 220 - Manual (Page 51)

Settings
51
Transport
Select the protocol for transport layer communication through this
setting.
Offer ICE
Choose whether you want to use ICE or not.
Codec 1-5
You can select the preferred order for the potential used codec. The
available options are G.711 ulaw, G.711 alaw, GSM, G.726-32 and
G.729a.
Packet size
Select the packet size in bytes. It affects only ulaw and alaw codecs
(other codecs have fixed packet size). Eighty (10 ms), 160 (20 ms),
240 (30 ms) and 320 (40 ms) bytes are available.
Setup Advanced
NETWORK
With these settings you can set up the basic network settings of your
phone. The web interface for this looks like the following:
DHCP
Turn on or off the use of DHCP with this option.
IP address
You can change the IP address of the device through this setting.
Changing this parameter requires a reboot. This parameter is
mandatory in order to enable the ethernet connection.
Netmask
Change the netmask for the device. Changing this parameter also
requires a reboot.
Phone name
Change the hostname of the phone here. If this parameter is available,
it is used for identifying the device in SIP signaling.