US 11,895,215 B2
Application server access method and terminal
Binjun Liu, Shanghai (CN); Yuwei Fan, Shanghai (CN); Fusheng Shen, Shanghai (CN); Weichen Zhu, Shenzhen (CN); Lixin Lin, Shanghai (CN); and Ying Zhu, Shanghai (CN)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Appl. No. 17/910,711
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
PCT Filed Mar. 4, 2021, PCT No. PCT/CN2021/079121
§ 371(c)(1), (2) Date Sep. 9, 2022,
PCT Pub. No. WO2021/179990, PCT Pub. Date Sep. 16, 2021.
Claims priority of application No. 202010167415.3 (CN), filed on Mar. 11, 2020.
Prior Publication US 2023/0171330 A1, Jun. 1, 2023
Int. Cl. H04L 61/4511 (2022.01); H04L 69/167 (2022.01); H04L 101/659 (2022.01)
CPC H04L 69/167 (2013.01) [H04L 61/4511 (2022.05); H04L 2101/659 (2022.05)] 17 Claims
OG exemplary drawing
 
1. A communications system, comprising a terminal, a domain name system server, and an application server, wherein:
the terminal is configured to:
receive a first operation of a user, wherein the first operation indicates to access a first domain name; and
send a first domain name resolution request to the domain name system server, wherein the first domain name resolution request is used to request an IPv4 address and an IPv6 address corresponding to the first domain name;
the domain name system server is configured to return, according to the first domain name resolution request, the IPv4 address and the IPv6 address corresponding to the first domain name to the terminal; and
the terminal is further configured to:
send a first connection request to the application server, wherein the first connection request comprises the IPv6 address corresponding to the first domain name;
in response to determining that connection to the application server by using the IPv6 address fails, set the first domain name corresponding to the IPv6 address to restricted information;
receive a second operation of the user, wherein the second operation indicates to re-access the first domain name;
send a second connection request to the application server, wherein the second connection request comprises the IPv4 address corresponding to the first domain name; and
in response to determining that air-interface communication of the terminal is normal and determining that a retransmission timer comprises an IPv6-type socket, a status of the IPv6-type socket is a preset state, and a quantity of retransmission times of the first connection request is greater than a preset quantity of times, determine that the connection to the application server by using the IPv6 address fails.