US 7,068,647 B2 · System and method for routing IP packets

Abstract

System and method for routing packets for IP telephony. The system includes an IP telephone (IPT) and a Service Gateway (SG) coupled via a network. The SG receives a data packet from the IPT, including a private source IP address (SIPA), source port number (SPN), and destination information for an IP device, performs network address persistent port translation (NAPPT) on the data packet, and sends it to the IP device. NAPPT changes the private SIA to a public SIA, leaving the SPN unchanged. The SG receives a data packet from the IP device, including a public destination IP address (DIPA, i.e., said public SIPA), a destination port number (DPN, i.e., said SPN), and source information, NAPPTs the data packet, using the public DIPA and the DPN to identify the IPT, changing the public DIPA to the private SIPA, leaving the DPN unchanged, and sends the data packet to the IPT.

Claims43

Dependent claims

A method for performing IP telephony, comprising:

receiving an identifier from the IP telephone;
determining if the identifier is valid;
and
if the identifier is valid, assigning a range of port numbers to the IP telephone based on the identifier, wherein the IP telephone is operable to use at least a subset of the range of port numbers to send or receive IP communications;
a Service Gateway receiving a data packet from the IP telephone, wherein the data packet comprises a private source IP address of the IP telephone, a source port number, and destination information associated with an IP device;
the Service Gateway performing a network address persistent port translation (NAPPT) on the data packet, including storing translation information in a data structure, wherein the translation information comprises:
the private source IP address of the IP telephone;
a public IP address of the Service Gateway;
and
the assigned ports for the IP telephone;
and
the Service Gateway sending the data packet to the IP device.

9 more elements

A system for performing IP telephony, comprising:

a network;
an IP telephone;
a Service Gateway, wherein the Service Gateway is operable to couple to the IP telephone through the network;
wherein the Service Gateway is further operable to:
receiving an identifier from the IP telephone;
determining if the identifier is valid;
and
if the identifier is valid, assigning a range of port numbers to the IP telephone based on the identifier, wherein the IP telephone is operable to use at least a subset of the range of port numbers to send or receive IP communications;
receive a data packet from an IP telephone, wherein the data packet comprises a private source IP address, a source port number, and destination information associated with an IP device;
perform a network address persistent port translation (NAPPT) on the data packet, including storing translation information in a data structure, wherein the translation information comprises:
the private source IP address of the IP telephone;
a public IP address of the Service Gateway;
and
assigned ports for the IP telephone;
and
send the data packet to the IP device.

13 more elements

A memory medium comprised in a Service Gateway, wherein the memory medium is operable to store program instructions which are executable to perform:

receiving an identifier from the IP telephone;
determining if the identifier is valid;
if the identifier is valid, assigning a range of port numbers to the IP telephone based on the identifier, wherein the IP telephone is operable to use at least a subset of the range of port numbers to send or receive IP communications;
receiving a data packet from an IP telephone, wherein the data packet comprises a private source IP address, a source port number, and destination information associated with an IP device;
performing a network address persistent port translation (NAPPT) on the data packet, including storing translation information in a data structure, wherein the translation information comprises:
the private source IP address of the IP telephone;
a public IP address of the Service Gateway;
and
assigned ports for the IP telephone;
and
sending the data packet to the IP device.

8 more elements

Dependencies are inferred from the claim text.

System and method for routing IP packets

Life of this patent

System and method for routing IP packets

Life of this patent

Abstract

Claims43