# US 9,882,872 B2 · Method and apparatus for inter-domain routing based on as architecture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,872 B2 - Document ID: US9882872B2 - Status: Granted - Kind: B2 - Application number: 14/607,136 - Filed: 2015-01-28 - Published: 2015-11-26 - Granted: 2018-01-30 - Earliest claimed: 2014-05-26 - Assignees: Electronics and Telecommunications Research Institute - Applicants: Electronics and Telecommunications Research Institute - Inventors: Tae-Wan You; Woo-Jik Chun - Web page: https://patentgrep.com/patent/US9882872B2 ## CPC - H04L 61/3025: {Domain name generation or assignment} - G06F 16/9024: {Graphs; Linked lists (G06F16/9027 takes precedence)} - H04L 61/5007: Internet protocol [IP] addresses - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method and apparatus for inter-domain routing based on AS architecture includes retrieving route information for a destination IP address of a data packet received from a source host in a forwarding information base (FIB); requesting to obtain a domain locator corresponding to the destination IP address to the mapping system when the route information corresponding to the destination IP address is not retrieved; and performing routing by using the obtained domain locator and routing information that is previously stored in the routing information base (RIB) in which the source host is present. ## Claims ### Claim 1 A computer-implemented method for generating a domain locator in a hierarchical domain architecture, the method comprising: advertising by a upper domain at least one of an autonomous system number (ASN) and a domain locator thereof to a lower domain based on the relation between domains; and generating by the lower domain, which receives the at least one of an autonomous system number (ASN) and a domain locator from the upper domain, its own domain locator by using the received at least one of an ASN number and a domain locator of the upper domain and its own ASN number. ### Claim 2 (depends on 1) The computer-implemented method for generating a domain locator of claim 1, wherein the domain locator is a directed acrylic locator (DAL) expressing routing information to forward a packet to a transit core, which is a top-level in domains, in a dynamic acrylic graph (DAG) form. ### Claim 3 (depends on 1) The computer-implemented method for generating a domain locator of claim 1, wherein the step for advertising at least one of an autonomous system number (ASN) and a domain locator thereof includes: advertising by a transit core, which is a top-level domain, its own ASN number; and advertising by the rest upper domain, except the top-level domain, its own domain locator. ### Claim 4 (depends on 1) The computer-implemented method for generating a domain locator of claim 1, wherein the step for advertising at least one of an autonomous system number (ASN) and a domain locator thereof transmits its own tier number to the lower domain. ### Claim 5 (depends on 1) The computer-implemented method for generating, a domain locator of claim 1, wherein the relation between domains is one of provider-subscriber, peering and transit group. ### Claim 6 (depends on 1) The computer-implemented method for generating a domain locator of claim 1, further comprising generating by the lower domain, when it receives at least one of ASN number and domain locator from the upper domain, routing information to forward a packet to a transit core in a DAG form based on the received ASN number and store the routing information to a routing information base (RIB). ### Claim 7 (depends on 6) The computer-implemented method for generating a domain locator of claim 6, wherein the RIB includes next-hop information and next-hop gateway information by destination, wherein, the next-hop information by destination is expressed by ASN and the next-hop gateway information is expressed by IP address. ### Claim 8 (depends on 1) The computer-implemented method for generating a domain locator of claim 1, further comprising registering a DAL generated by each domain to a mapping system by mapping onto an IP address block. ### Claim 9 A domain gateway apparatus comprising: a processor; and a memory storing program instructions that, when executed by the processor, causes the processor to: receive at least one of an ASN number and a domain locator of its own upper domain from a gateway apparatus of the upper domain; generate its own domain locator by using the received at least one of an ASN number and a domain locator of the upper domain and its own ASN number; and advertise the domain locator generated by using its own ASN number to its own lower domain. ### Claim 10 (depends on 9) The domain gateway apparatus of claim 9, wherein the domain locator expresses routing information to forward a packet to a transit core which is a top-level in the domains in a DAG form.