Extended search is being performed and may take significant time.
Destination user agent received INVITE and it alerting user of call.
181 Call is being Forwarded
Servers can optionally send this response to indicate a call is being forwarded. More commonly, you’ll receive a 301 Moved Permanently or 302 Moved Temporarily.
183 Session in Progress
Used to send extra information for a call which is still being setup.
199 Early Dialog Terminated
Can be used by User Agent Server to indicate to upstream SIP entities that an early dialog has been terminated.
Indicates the request was successful.
Indicates that the request has been accepted for processing, but the processing has not been completed.
204 No Notification
Indicates the request was successful, but the corresponding response will not be received.
300 Multiple Choices
The address resolved to one of several options for the user or client to choose between, which are listed in the message body or the message’s Contact fields.
301 Moved Permanently
The original Request-URI is no longer valid, the new address is given in the Contact header field, and the client should update any records of the original Request-URI with the new value.
302 Moved Temporarily
The client should try at the address in the Contact field. If an Expires field is present, the client may cache the result for that period of time.
305 Use Proxy
The Contact field details a proxy that must be used to access the requested destination.
380 Alternative Service
The call failed, but alternatives are detailed in the message body.
400 Bad Request
The request could not be understood due to malformed syntax.
The request requires user authentication. This response is issued by UASs and registrars.
402 Payment Required
Reserved for future use.
The server understood the request, but is refusing to fulfill it.
404 Not Found
The server has definitive information that the user does not exist at the domain specified in the Request-URI. This status is also returned if the domain in the Request-URI does not match any of the domains handled by the recipient of the request.
405 Method Not Allowed
The method specified in the Request-Line is understoof, but not alloed for the address identified by the Request-URI.
CDMA phones are activated remotely, by the carrier, using the phone’s serial number, known as the ESN. Since each carrier has a database of all the ESNs that are approved for its network, this lets most CDMA carriers refuse to activate phones not originally intended for their network.
GSM phones are associated with what’s called a SIM card, or Subscriber Identity Module. This card, about the size of a fingertip and the thickness of a piece of paperboard, carries an encrypted version of all the information needed to identify the wireless account to the network. On most GSM phones the SIM card is usually under the battery.
A wireless technology from Motorola combining the capabilities of a digital cellular telephone, two-way radio, alphanumeric pager and data/fax modem in a single network. Nextel is the brand name for Sprint’s line of iDEN walkie-talkie enabled phones – this feature is called “Direct Connect”. Boost Mobile is a subsidiary of Sprint Nextel, providing an economy prepaid service (MVNO) for the youth market, using the same iDEN technology as Nextel, and using Sprint Nextel’s iDEN network. Boost also offers unlimited service using CDMA phones and Sprint Nextel’s CDMA network.
A pen register, or dialed number recorder (DNR), is an electronic device that records all numbers called from a particular telephone line.
Trap and trace
A trap and trace device is similar to a pen register. A trap and trace device would show what numbers had called a specific telephone, i.e. all incoming phone numbers.