Grandstream Networks HT502 DNS Mode, User ID is Phone, Number, SIP Registration, Local RTP port

	DNS Mode	One from the 3 modes are available for “DNS Mode” configuration:
		-A Record (for resolving IP Address of target according to domain name)
		-SRV (DNS SRV resource records indicates how to find services for various protocols)
		-NAPTR/SRV (Naming Authority Pointer according to RFC 2915)
		One mode can be chosen for the client to look up server.
		The default value is “A Record”
	User ID is Phone	If the HT502 has an assigned PSTN telephone number, this field should be set to
	Number	“Yes”. Otherwise, set to “No”. If set to “Yes”, a	“user=phone” parameter will be
		appended to the “From” header in SIP request.
	SIP Registration	Controls whether the HT502 needs to send REGISTER messages to the proxy server.
		The default setting is Yes.
	Unregister on Reboot	Default is No. If set to Yes, the SIP user’s registration information will be cleared on
		reboot.
	Outgoing Call without	Default is No. If set to “Yes,” user can place outgoing calls even when not registered (if
	Registration	allowed by Internet Telephone Service Provider) but is unable to receive incoming
		calls.
	Register Expiration	This parameter allows the user to specify the time frequency (in minutes) the HT502
		refreshes its registration with the specified registrar. The default interval is 60 minutes
		(or 1 hour). The maximum interval is 65535 minutes (about 45 days).
	Registration Retry Wait	Retry registration if the process failed. Default is 30 seconds.
	Time
	Local SIP port	Defines the local SIP port the HT502 will listen and transmit. The default value for FXS
		port 1 is 5060. The default value for FXS port 2 is 5062.
	Local RTP port	Defines the local RTP-RTCP port pair the HT502 will listen and transmit. It is the base
		RTP port for channel 0. When configured,
		channel 0 uses this port _value for RTP and the port_value+1 for its RTCP; channel 1
		uses port_value+2 for RTP and port_value+3 for its RTCP.
		The default value for FXS port 1 is 5004. The default value for FXS port 2 is 5012.
	Use Random Port	This parameter forces the random generation of both the local SIP and RTP ports when
		set to Yes. This is usually necessary when multiple HT502 are behind the same NAT.
	Refer to Use Target	Default is NO. If set to YES, then for Attended Transfer, the “Refer-To” header uses the
	Contact	transferred target’s Contact header information.
	Transfer on Conference	Default is No. In which case if the conference originator hangs up the conference will
	Hang up	be terminated. When option YES is chosen, originator will transfer other parties to
		each other so that B and C can choose either to continue the conversation or
		hang up.
	Enable Ring-Transfer	Default is No, this will create a Semi-Attendant Transfer. When set to Yes, device can
		transfer the call upon receiving ring back tone.
	Disable Bellcore Style	Default is No. you can make a Conference by pressing ‘Flash’ key. If set to Yes, you
	3-Way Conference	need to dial *23 + second callee number.
	Remove OBP from	Default is No. When option YES is chosen, the Out Bound Proxy will be removed from
	Route Header	Route header.
	Support SIP Instance ID	Default is Yes. If set to Yes, the contact header in REGISTER request will contain SIP
		Instance ID as defined in IETF SIP Outbound draft.
	Validate incoming SIP	Default is No. If set to yes all incoming SIP messages will be strictly validated
	message	according to RFC rules. If message will not pass validation process, call will be
		rejected.
	Check SIP User ID for	Default is No. Check the incoming SIP User ID in Request URI. If they don’t match, the
	incoming INVITE	call will be rejected. If this option is enabled, the device will not be able to make direct
		IP calls.
Grandstream Networks, Inc.		HT-502 User Manual	Page 24 of 32
		Firmware Version 1.0.4.2	Last Updated: 06/2011