When dialing internal destination numbers using an international format (for example, 00049xxx100) from a mobile station, the PABX number for the system must be unique (DID-enabled). Non-DID-enabled trunks are not suitable for this type of dialing (or may only be suitable under certain conditions), as internal destination numbers are dialed via the CO and costs may be incurred as a result.   DISA and callback must use the local system TDM trunks (no SIP carrier and no IP networking).

Subject	HiPath 3800	HiPath 3550    HiPath 3500	HiPath 3350    HiPath 3300
Feature available in	x	x	x
Hardware requirements	-
Software requirements	V7 or later	V7 or later	V7 or later
General requirements	-

Subject	Dependency/Restriction
DISA phone number	The DISA phone number cannot be dialed via the SIP carrier or over networked systems; it can only be called directly over the fixed network (TDM trunks).
Callback	The "Callback" function is to return calls with the aim of relieving the costs for a mobile station. First, the mobile station calls the system's callback port. This call is ended by the system without accepting the call. The subsequent system callback to the mobile station must be via the system's local TDM trunks (not via SIP carrier or IP networking). Configuration is via LCR.
Callback	Mobility Entry is not supported behind SIP provider interfaces. This means that the "Callback" function is also not supported. The same restriction applies to IP networks.   Mobility Entry is only released for nodes also connected to the CO.
External destination numbers	The dialing of external destination numbers from mobile stations is controlled in the system due to the LCR configuration. External destinations can therefore be dialed via the TDM or SIP carrier.
Internal destination numbers	When dialing internal destination numbers using an international format (for example, 00049xxx100) from a mobile station, the PABX number for the system must be unique (DID-enabled). Non-DID-enabled trunks are not suitable for this type of dialing (or may only be suitable under certain conditions), as internal destination numbers are dialed via the CO and costs may be incurred as a result.
CLIP No Screening	To display a caller ID on mobile stations, the ID must be transmitted without being checked by the carrier.
Mobile station CLIP	For quick system dial-up via DISA, the mobile station must transmit CLIP information. The carrier must provide this.
LCR administration	As some providers do not accept destination numbers with an individual international prefix, the system must remove the prefix from the destination number. This can be administered with least cost routing (LCR).
Trunks (B channels)	See table above.
Emergency numbers	If a mobile station dials an emergency number, the call is connected by the system. This means, however, that the location of the mobile station cannot be determined. For this reason, stations must not be permitted to dial emergency numbers. Emergency numbers must also be dialed directly from the stations.
MULAP	•   Only one virtual station is permitted in a MULAP.  •   Only GSM telephones and home workstations are permitted as mobile stations in a MULAP; CMI mobile units are not permitted.
Call pickup in a MULAP	•   If there is only one mobile station and one stationary station in a MULAP, the stationary station can press the DSS key to pick up a call directed to the mobile station.  •   If there are multiple mobile stations and one stationary station in a MULAP, call pickup is only possible for the first mobile station of the MULAP.