Providing telephony services to terminals behind a firewall and/or a network address translator
First Claim
1. A method for use in communications involving a first terminal that is coupled to a first side of a firewall and network address translator, the method comprising:
- sending, by the first terminal, a first message identifying the first terminal to a node on a second side of the firewall and network address translator, the first message identifying the first terminal as available for a call session;
receiving, by the first terminal, a second message from the node, wherein the first and second messages between the first terminal and the node cause creation of a signaling connection through the firewall and network address translator and creation of a mapping between a first address of the first terminal and a second address of the first terminal, where the first address is an address assigned to the first terminal on the first side of the firewall and network address translator, and where the second address is an address assigned to the first terminal on the second side of the firewall and network address translator;
repeatedly sending keep-alive messages to maintain the existing signaling connection through the firewall and network address translator and to thereby maintain the mapping at the firewall and network address translator, wherein failure to repeatedly send the keep-alive messages will result in the existing signaling connection being closed and the mapping being removed;
communicating messages, by the first terminal, with the node over the existing signaling connection maintained through the firewall and network address translator to establish a first call session with a second terminal using a first call session connection, the first call session connection being different from the existing signaling connection; and
exchanging media packets with the second terminal via the first call session connection.
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0 Petitions
Accused Products
Abstract
A method and apparatus is provided to allow telephony or other types of media communications and services to be provided for a device (24) having a private network address that resides behind a firewall and network address and port translation (NAPT) module (which is not aware of the underlying protocol for the communications and services). Examples of the underlying protocol includes the Session Initiation Protocol (SIP) and Real-Time Protocol (RTP). A path through the firewall and NAPT module is defined by use of keep-alive messages communicated through the firewall and NAPT module. Addresses that are allocated by the firewall and NAPT module are associated with the device (24) for both signaling and media communications. A feature of the firewall that enables the provision of telephony and media communications through the firewall that is protocol-unaware is that the firewall allows responses to messages initiated by the device back through the firewall.
93 Citations
18 Claims
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1. A method for use in communications involving a first terminal that is coupled to a first side of a firewall and network address translator, the method comprising:
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sending, by the first terminal, a first message identifying the first terminal to a node on a second side of the firewall and network address translator, the first message identifying the first terminal as available for a call session; receiving, by the first terminal, a second message from the node, wherein the first and second messages between the first terminal and the node cause creation of a signaling connection through the firewall and network address translator and creation of a mapping between a first address of the first terminal and a second address of the first terminal, where the first address is an address assigned to the first terminal on the first side of the firewall and network address translator, and where the second address is an address assigned to the first terminal on the second side of the firewall and network address translator; repeatedly sending keep-alive messages to maintain the existing signaling connection through the firewall and network address translator and to thereby maintain the mapping at the firewall and network address translator, wherein failure to repeatedly send the keep-alive messages will result in the existing signaling connection being closed and the mapping being removed; communicating messages, by the first terminal, with the node over the existing signaling connection maintained through the firewall and network address translator to establish a first call session with a second terminal using a first call session connection, the first call session connection being different from the existing signaling connection; and exchanging media packets with the second terminal via the first call session connection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for use in communications involving a first terminal that is coupled to a first side of a firewall and network address translator, the method comprising:
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sending, by the first terminal, a first message identifying the first terminal to a node on a second side of the firewall and network address translator, the first message identifying the first terminal as available for a call session; receiving, by the first terminal, a second message from the node, wherein the first and second messages between the first terminal and the node cause creation of a signaling connection through the firewall and network address translator and creation of a mapping between a first address of the first terminal and a second address of the first terminal, where the first address is an address assigned to the first terminal on the first side of the firewall and network address translator, and where the second address is an address assigned to the first terminal on the second side of the firewall and network address translator; repeatedly sending keep-alive messages to maintain the existing signaling connection through the firewall and network address translator and to thereby maintain the mapping at the firewall and network address translator, wherein failure to repeatedly send the keep-alive messages will result in the existing signaling connection being closed and the mapping being removed; wherein maintaining the existing signaling connection comprises maintaining an existing Session Initiation Protocol (SIP) signaling connection between the first terminal and the node through the firewall and network address translator; communicating messages, by the first terminal, with the node over the existing SIP signaling connection maintained through the firewall and network address translator to establish a first call session with a second terminal using a first call session connection, the first call session connection being different from the existing SIP signaling connection; and exchanging media packets with the second terminal via the first call session connection. - View Dependent Claims (13)
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14. A device for use in communications through a firewall and network address translator, wherein the device is for provision on a first side of the firewall and network address translator, the device comprising:
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an interface configured to communicate messages with a node on a second side of the firewall and network address translator, the communication of the messages with the node to create a signaling connection through the firewall and network address translator and to create a mapping between a first address of the device and a second address of the device, where the first address is an address assigned to the device on the first side of the firewall and network address translator, and where the second address is an address assigned to the device on the second side of the firewall and network address translator, the messages identifying the device as available for a call session; and a controller configured to; repeatedly send keep-alive messages to maintain the existing signaling connection through the firewall and network address translator and to thereby maintain the mapping at the firewall and network address translator, wherein failure to repeatedly send the keep-alive messages will result in the existing signaling connection being closed and the mapping being removed, wherein the existing signaling connection comprises an existing Session Initiation Protocol (SIP) signaling connection; communicate messages with the node over the existing signaling connection maintained through the firewall and network address translator to establish a first call session with the node using a first call session connection, the first call session connection being different from the existing signaling connection; and exchange media packets with the node via the first call session connection. - View Dependent Claims (15, 16, 17, 18)
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Specification