Aastra Telecom 55I, 57I CT, 53I manual Phones

Configuring Network and Session Initiation Protocol (SIP) Features

Global SIP Settings

					Configuring
	Aastra Web UI
Step	Action
5	Enter a "Customized Codec Preference List". For example,
		payload=8;ptime=10;
		silsupp=on;
		payload=0;ptime=10;
		silsupp=off
	Valid values are:
			Attribute	Value	the
			payload	0 for G.711 u-Law
				8 for G.711 a-Law
				18 for G.729a	IP
			ptime (in milliseconds)	5, 10, 15, 20.....90
			silsupp	on
				off	Phones
	For this parameter, you specify a customized codec list which allows you to use the preferred Codecs
	for this IP phone. Default for the “Customized Codec Preference List” is blank.
6	Select a method to use from the “DTMF Method” list box. Valid values are RTP, SIP Info, Both.
	Default is RTP.
	Note: You can configure the DTMF Method on a global or per-line basis.
7	Select the type of RTP encryption to use from the “RTP Encryption” list box. Valid values are SRTP
	Disabled, SRTP Preferred, or SRTP Only. Default is SRTP Disabled.
	Note: You can configure RTP Encryption on a global or per-line basis.
8	The “Silence Suppression” field is enabled by default. Disable this field by unchecking the check
	box.
	When enabled, the phone negotiates whether or not to use silence suppression. Disabling this
	feature forces the phone to ignore any negotiated value.
9	Click		to save your changes.

41-001160-00, Release 2.1, Rev 04 4-73