# US 7,133,923 B2 · System and method for assisting in controlling real-time transport protocol flow through multiple networks via screening > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,133,923 B2 - Document ID: US7133923B2 - Status: Granted - Kind: B2 - Application number: 09/844,984 - Filed: 2001-04-27 - Published: 2002-11-14 - Granted: 2006-11-07 - Earliest claimed: 2000-12-11 - Assignees: Acme Packet, Inc. - Inventors: Patrick J. MeLampy; Andrew D. Ory; Clifford M. Spencer; Robert F. Penfield; Peter S. Commerford; Stephen T. Voto; Cynthia E. Arens; Rebecca A. Pedersen - Web page: https://patentgrep.com/patent/US7133923B2 ## CPC - H04L 65/1043: Gateway controllers, e.g. media gateway control protocol [MGCP] controllers - H04L 45/121: by minimising delays - H04L 45/3065: {for real time traffic} - H04L 65/1104: Session initiation protocol [SIP] - H04M 3/42144: {by service provider} - H04M 7/128: {Details of addressing, directories or routing tables} - H04Q 3/0025: {Provisions for signalling} - H04Q 3/0045: {involving hybrid, i.e. a mixture of public and private, or multi-vendor systems} - H04Q 3/66: Traffic distributors - H04L 69/22: Parsing or analysis of headers - H04Q 2213/13034: A/D conversion, code compression/expansion - H04Q 2213/13097: Numbering, addressing - H04Q 2213/13103: Memory - H04Q 2213/13106: Microprocessor, CPU - H04Q 2213/13138: Least cost routing, LCR - H04Q 2213/13141: Hunting for free outlet, circuit or channel - H04Q 2213/13166: Fault prevention - H04Q 2213/13176: Common channel signaling, CCS7 - H04Q 2213/13204: Protocols - H04Q 2213/13299: Bus - H04Q 2213/13332: Broadband, CATV, dynamic bandwidth allocation - H04Q 2213/13345: Intelligent networks, SCP - H04Q 2213/13348: Channel/line reservation - H04Q 2213/13352: Self-routing networks, real-time routing - H04Q 2213/13376: Information service, downloading of information, 0800/0900 services - H04Q 2213/13384: Inter-PBX traffic, PBX networks, e.g. corporate networks - H04Q 2213/13389: LAN, internet - H04Q 2213/13395: Permanent channel, leased line - H04Q 2213/13399: Virtual channel/circuits - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) ## Abstract A system for assisting in controlling real-time transport protocol flow through multiple networks via screening is disclosed. The system utilizes a transceiver, a memory having logic stored therein defining functions to be performed by the system, and a processor. The processor is configured by the memory to perform the functions of: determining if route information received by the transceiver is from an external source or an internal source; if the route information is from an external source, performing a first internal screen of the route information, wherein a destination address defined by the received route information is compared to a local destination address defined by the first internal screen; and if the route information is from an internal source, performing a second internal screen of the route information, wherein an origin address defined by the received route information is compared to a local origin address defined by the second internal screen. ## Claims ### Claim 1 A system for screening a real-time transport protocol route advertisement communicated between adjacent Internet telephony administrative domains prior to comparing an advertised route to a policy, comprising: a database server confimired to store at least one policy, the at least one policy comprising attributes associated with one or more routes; and a plurality of session routers in communication with the database server and configured to determine a source of a real-time transport protocol route advertisement; when it is determined that a real-time transnort protocol route advertisement received at a respective session router is from an Internet telephony administrative domain managed by another administrative entity than the administrative entity that manages the respective session router, the session router is configured to perform destination screen of said route advertisement, wherein a destination address defined by said received route advertisement is compared to a destination address, and when it is determined that a real-time transport protocol route advertisement received at a respective session router is from the administrative entity that manages the respective session router, the session router is configured to perform an origin screen of said route information, wherein an origin address defined by said received route advertisement is compared to an origin address. ### Claim 2 (depends on 1) The system of claim 1, wherein the respective session router discards said received route advertisement, when said destination address defined by said received route advertisement does not match said destination address defined by said destination screen. ### Claim 3 (depends on 1) The system of claim 1, wherein the respective session router determines which of said destination address defined by said received route advertisement and said destination address contains the greatest number of characters, when a portion of said destination address defined by said received route advertisement matches a portion of said destination address defined by said destination screen. ### Claim 4 (depends on 3) The system of claim 3, wherein the respective session router retains said destination address defined by said destination screen and discards said destination address defined by said received route advertisement, when said destination address defined by said destination screen contains a greater number of characters than said destination address defined by said received route advertisement. ### Claim 5 (depends on 3) The system of claim 3, wherein the respective session router stores said destination address defined by said received route advertisement for future comparison to the at least one policy, when said destination address defined by said destination screen contains a lesser number of characters than said destination address defined by said received route advertisement. ### Claim 6 (depends on 1) The system of claim 1, wherein the format of said destination address conforms to at least one of E.164 style addresses, Internet style addresses, session initiation protocol telephone addresses and non-session initiation protocol telephone addresses. ### Claim 7 (depends on 1) The system of claim 1, wherein the respective session router stores said received route advertisement for future comparison to a policy, when said received route advertisement does not have said origin address. ### Claim 8 (depends on 1) The system of claim 1, wherein the respective session router discards said received route advertisement when said origin address defined by said received route advertisement does not match said origin address defined by said destination screen. ### Claim 9 (depends on 1) The system of claim 1, wherein the respective session router determines which of said origin address defined by said received route advertisement and said origin address defined by said destination screen contains the greatest number of characters, when a portion of said origin address defined by said received route advertisement matches a portion of said origin address defined by said destination screen. ### Claim 10 (depends on 9) The system of claim 9, wherein the respective session router retains said origin address defined by said destination screen and discarding said origin address defined by said received route advertisement, when said origin address defined by said destination screen contains a greatest number of characters than said origin address defined by said received route advertisement. ### Claim 11 (depends on 9) The system of claim 9, wherein the respective session router retains said origin address defined by said received route advertisement for future comparison to a policy, when said origin address defined by said destination screen contains a lesser number of characters than said origin address defined by said received route advertisement. ### Claim 12 (depends on 1) The system of claim 1, wherein the respective session router reads a received carrier attribute provided by said received route advertisement, wherein said received carrier attribute describes a source of said received route advertisement, prior to comparing said received route advertisement to said at least one policy. ### Claim 13 (depends on 12) The system of claim 12, wherein the respective session router discards said received route advertisement prior to comparing said received route advertisement to said at least one policy, when a received carrier name, defined by said received carrier attribute, does not match a carrier name. ### Claim 14 (depends on 12) The system of claim 12, wherein the respective session router discards said received route advertisement prior to comparing said received route advertisement to said at least one policy, when a received carrier days of availability, defined by said received carrier attribute, does not match a carrier days of availability. ### Claim 15 (depends on 12) The system of claim 12, wherein the respective session router discards said received route advertisement prior to comparing said received route advertisement to said at least one policy, when a received carrier hours of availability, defined by said received carrier attribute, does not match a carrier hours of availability. ### Claim 16 (depends on 12) The system of claim 12, wherein the respective session router discards said received route advertisement prior to comparing said received route advertisement to said at least one policy, when a received carrier time of availability, defined by said received carrier attribute, does not match a carrier time of availability. ### Claim 17 (depends on 12) The system of claim 12, wherein the respective session router discards said received route advertisement prior to comparing said received route advertisement to said at least one policy, when a received carrier cost, defined by said received carrier attribute, does not match a carrier cost. ### Claim 18 (depends on 1) The system of claim 1, wherein the format of said origin address conforms to at least one of E.164 style addresses, Internet style addresses, session initiation protocol telephone addresses, and non-session initiation protocol telephone addresses. ### Claim 19 (depends on 1) The system of claim 1, wherein said route advertisement is provided within a telephony routing over Internet protocol update message. ### Claim 20 A method of screening a real-time transport protocol route advertisement prior to comparing said route advertisement to a policy, comprising the steps of: receiving a route advertisement describing a route from a first endpoint to a second endpoint at a session router; determining when said route advertisement is received from an an Internet telephony administrative domain managed by another administrative entity than the administrative entity that manages the session router; when said route advertisement is from an Internet telephony administrative domain managed by another administrative entity, performing a destination screen of said route advertisement, wherein a destination address defined by said received route advertisement is compared to a destination address defined by said destination screen; and when said route advertisement is from the administrative entity that manages the session router, performing an origin screen of said route advertisement, wherein an origin address defined by said received route advertisement is compared to an origin address defined by said origin screen. ### Claim 21 (depends on 20) The method of claim 20, wherein said step of comparing said destination address defined by said received route advertisement to said destination address defined by said destination screen further comprises the step of: when said destination address defined by said received route advertisement does not match said destination address defined by said destination screen, discarding said received route advertisement. ### Claim 22 (depends on 20) The method of claim 20, wherein said step of comparing said destination address defined by said received route advertisement to said destination address defined by said destination screen, further comprises the steps of: when a portion of said destination address defined by said received route advertisement matches a portion of said destination address defined by said destination screen, determining which of said destination address defined by said received route advertisement and said destination address defined by said destination screen contains the greatest number of characters. ### Claim 23 (depends on 22) The method of claim 22, further comprising the step of: when said destination address defined by said destination screen contains a greater number of characters than said destination address defined by said received route advertisement, keeping said destination address defined by said destination screen and discarding said destination address defined by said received route advertisement. ### Claim 24 (depends on 22) The method of claim 22, further comprising the step of: when said destination address defined by said destination screen contains a lesser number of characters than said destination address defined by said received route advertisement, storing said destination address defined by said received route advertisement for future comparison to a policy. ### Claim 25 (depends on 20) The method of claim 20, wherein the format of said destination address conforms to at least one of E.164 style addresses, Internet style addresses, session initiation protocol telephone addresses, and non-session initiation protocol telephone addresses. ### Claim 26 (depends on 20) The method of claim 20, further comprising the step of: when said received route advertisement does not have said origin address, storing said received route advertisement for future comparison to a policy. ### Claim 27 (depends on 20) The method of claim 20, wherein said step of comparing said origin address defined by said received route advertisement to said origin address defined by said destination screen, further comprises the step of: when said origin address defined by said received route advertisement does not match said origin address defined by said destination screen, discarding said received route advertisement. ### Claim 28 (depends on 20) The method of claim 20, wherein said step of comparing said origin address defined by said received route advertisement to said origin address defined by said destination screen, further comprises the steps of: when a portion of said origin address defined by said received route advertisement matches a poition of said origin address defined by said destination screen, determining which of said origin address defined by said received route advertisement and said origin address defined by said destination screen contains the greater number of characters. ### Claim 29 (depends on 28) The method of claim 28, further comprising the step of: when said origin address defined by said destination screen contains a greater number of characters than said origin address defined by said received route advertisement, keeping said origin address defined by said destination screen and discarding said origin address defined by said received route advertisement. ### Claim 30 (depends on 28) The method of claim 28, further comprising the step of: when said origin address defined by said destination screen contains a lesser number of characters than said origin address defined by said received route advertisement, storing said origin address defined by said received route advertisement for future comparison to a policy. ### Claim 31 (depends on 20) The method of claim 20, further comprising the step of: reading a received carrier attribute provided by said received route advertisement, wherein said received carrier attribute describes a source of said received route advertisement, prior to comparing said received route advertisement to said policy. ### Claim 32 (depends on 31) The method of claim 31, further comprising the step of: when a received carrier name, defined by said received carrier attribute, does not match a local carrier name, discarding said received route advertisement prior to comparing said received route advertisement to said policy. ### Claim 33 (depends on 31) The method of claim 31, further comprising the step of: when a received carrier days of availability, defined by said received carrier attribute, does not match a carrier days of availability, discarding said received route advertisement prior to comparing said received route advertisement to said policy. ### Claim 34 (depends on 31) The method of claim 31, further comprising the step of: when a received carrier hours of availability, defined by said received carrier attribute, does not match a carrier hours of availability, discarding said received route advertisement prior to comparing said received route advertisement to said policy. ### Claim 35 (depends on 31) The method of claim 31, further comprising the step of: when a received carrier time of availability, defined by said received carrier attribute, does not match a carrier time of availability, discarding said received route advertisement prior to comparing said received route advertisement to said policy. ### Claim 36 (depends on 31) The method of claim 31, further comprising the step of: when a received carrier cost, defined by said received carrier attribute, does not match a carrier cost, discarding said received route advertisement prior to comparing said received route advertisement to said policy. ### Claim 37 A system for screening real-time transport protocol route advertisements prior to comparing said routes to a policy, comprising: means for receiving a route advertisement describing a route that traverses one or more Internet telephony administrative domains; means for identifying a managing entity that controls an originating device and a managing entity that controls a destination device defined by the route advertisement, which is logically connected to said means for receiving; means for performing a destination screen of said route advertisement, which is configured to compare a destination address defined by received route advertisement to a destination address defined by said destination screen, which is logically connected to said means for receiving and said means for identifying; and means for performing an orgin screen of said route advertisement, which is configured to compare an origin address defined by said received route advertisement to an origin address defined by said origin screen, which is logically connected to said means for receiving, said means for identifying, and said means for performing. ### Claim 38 (depends on 37) The system of claim 37, further comprising a means for discarding said route advertisement when said destination address defined by said received route advertisement does not match said destination address defined by said destination screen. ### Claim 39 (depends on 37) The system of claim 37, further comprising a means for determining which of said destination address defined by said received route advertisement and said destination address defined by said destination screen contains a greater number of characters when a portion of said destination address defined by said received route advertisement matches a portion of said destination address defined by said destination screen. ### Claim 40 (depends on 39) The system of claim 39, further comprising a means for keeping said destination address defined by said destination screen and discarding said destination address defined by said received route advertisement when said destination address defined by said destination screen contains a greater number of characters than said destination address defined by said received route advertisement. ### Claim 41 (depends on 39) The system of claim 39, further comprising a means for storing said destination address defined by said received route advertisement for future comparison to a policy when said destination address defined by said destination screen contains a lesser number of characters than said destination address defined by said received route advertisement. ### Claim 42 (depends on 37) The system of claim 37, wherein the format of said destination address conforms to at least one of E.164 style addresses, Internet style addresses, session initiation protocol telephone addresses, and non-session initiation protocol telephone addresses. ### Claim 43 (depends on 37) The system of claim 37, further comprising a means for storing said received route advertisement for future comparison to a policy when said received route advertisement does not have said origin address. ### Claim 44 (depends on 37) The system of claim 37, further comprising a means for discarding said received route advertisement when said origin address defined by said received route advertisement does not match said origin address defined by said destination screen. ### Claim 45 (depends on 37) The system of claim 37, further comprising a means for determining which of said origin address defined by said received route advertisement and said origin address defined by said destination screen it contains a greater number of characters when a portion of said origin address defined by said received route advertisement matches a portion of said origin address defined by said destination screen. ### Claim 46 (depends on 45) The system of claim 45, further comprising a means for keeping said origin address defined by said destination screen and discarding said origin address defined by said received route advertisement when said origin address defined by said destination screen contains a greater number of characters than said origin address defined by said received route advertisement. ### Claim 47 (depends on 45) The system of claim 45, further comprising a means for storing said origin address defined by said received route advertisement for future comparison to a policy when said origin address defined by said destination screen contains a lesser number of characters than said origin address defined by said received route advertisement. ### Claim 48 (depends on 37) The system of claim 37, further comprising a means for reading a received carrier attribute provided by said received route advertisement, wherein said received carrier attribute describes a source of said received route advertisement, prior to comparing said received route advertisement to said policy. ### Claim 49 (depends on 48) The system of claim 48, further comprising a first means for discarding said received route advertisement prior to comparing said received route advertisement to said policy when a received carrier name, defined by said received carrier attribute, does not match a carrier name. ### Claim 50 (depends on 48) The system of claim 48, further comprising a second means for discarding said received route advertisement prior to comparing said received route advertisement to said policy when a received carrier days of availability, defined by said received carrier attribute, does not match a carrier days of availability. ### Claim 51 (depends on 48) The system of claim 48, further comprising a third means for discarding said received route advertisement prior to comparing said received route advertisement to said policy when a received carrier hours of availability, defined by said received carrier attribute, does not match a carrier hours of availability. ### Claim 52 (depends on 48) The system of claim 48, further comprising a fourth means for discarding said received route advertisement prior to comparing said received route advertisement to said policy when a received carrier time of availability, defined by said received carrier attribute, does not match a carrier time of availability. ### Claim 53 (depends on 48) The system of claim 48, further comprising a fifth means for discarding said received route advertisement prior to comparing said received route advertisement to said policy when a received carrier cost, defined by said received carrier attribute, does not match a carrier cost.