Abstract: IP addresses are presently becoming a scarce resource, even in private IP address domains. Commonly therefore network address translators are used to map a large number of private addresses to a relatively small number of public IP address, or even map addresses between two different IP address domains. However, network address translators do not readily pass voice set-up protocols such as SIP and VoIP packets. By modifying a call server and providing an intelligent network address translator, conventional media gateways may be caused to use the intelligent address translator to route VoIP packets between IP domains having overlapping address spaces.

Abstract: A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP s approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls. Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The database also has information about maximum bandwidths for the link associated with each middlebox.

Abstract: This invention relates to a carrier (service provider) hosted enterprise voice over internet protocol (VoIP) virtual private network (VPN) across a number of sites of an enterprise where said sites are located in a number of different countries. The enterprise VoIP VPN interfaces with the public switched telephone networks (PSTNs) in each of the countries via respective media gateways. The media gateways are controlled by a single network intelligence apparatus (call agent) of the carrier network which is located in one country but which controls all the media gateways interfacing the enterprise VoIP VPN with the PSTNs of the various countries through a network intelligence IP VPN provisioned on a public IP network. The arrangement of the invention negates the need for a network intelligence apparatus to be provisioned in each country in which the enterprise has sites serviced by the enterprise VoIP VPN.

Abstract: The invention provides a method of determining the degree of network address translation (NAT) traversing required to dynamically establish a bearer path within or out of a Service Provider hosted Enterprise VoIP VPN. Each media end point in the Enterprise IP VPN has associated with it a chain of the identities of a hierarchy of NAT functions behind which it resides with respect to an SP public IP network over which the Enterprise VoIP is hosted. By comparing the respective NAT function identity chains for an originating end point and a destination end point, a call agent can determine what, if any, NAT functions need to be traversed in the bearer path between the end points.

Abstract: A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP s approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls. Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The database also has information about maximum bandwidths for the link associated with each middlebox.

Abstract: A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls. Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The database also has information about maximum bandwidths for the link associated with each middlebox.

Abstract: IP addresses are presently becoming a scarce resource, even in private IP address domains. Commonly therefore network address translators are used to map a large number of private addresses to a relatively small number of public IP address, or even map addresses between two different IP address domains. However, network address translators do not readily pass voice set-up protocols such as SIP and VoIP packets. By modifying a call server and providing an intelligent network address translator, conventional media gateways may be caused to use the intelligent address translator to route VoIP packets between IP domains having overlapping address spaces.