As of my last knowledge update in September 2021, there are several manufacturers of Deep Packet Inspection (DPI) equipment, including some from China and other countries. Please note that the landscape might have changed since then. Here are a few manufacturers:

China:

1. Huawei: Huawei is a major Chinese tech company that offers networking and telecommunications equipment, including DPI solutions.
2. ZTE: ZTE is another prominent Chinese telecommunications equipment manufacturer that provides DPI technology as part of its networking solutions.
3. Netscout Systems (formerly known as Tektronix Communications): While not a Chinese company, Netscout has a presence in China and offers DPI solutions as part of its network monitoring and security offerings.
4. Qosmos (now part of Enea): Qosmos, which was acquired by Enea, offers DPI technology used for network analytics, cybersecurity, and other applications.
5. Inspur Group: A Chinese technology company that offers a range of products, including networking and communications equipment that may incorporate DPI capabilities.
6. Sunrise Technologies: A Chinese company specializing in network communication solutions, including DPI-based offerings for network optimization and security.
7. Ruijie Networks: Another Chinese networking company that provides DPI technology as part of its network management and security solutions.
8. Chinasoft International: While not exclusively focused on DPI, this Chinese IT services company may offer DPI-related products in the context of broader networking and security solutions.
9. Digital China Networks (DCN): A Chinese networking company that offers DPI solutions as part of its portfolio for network optimization and security.
10. FiberHome: Another Chinese telecommunications equipment manufacturer that provides DPI technology along with its networking solutions.
11. Yinlong Information Technology: A Chinese company specializing in network security solutions, including DPI-based offerings.
12. Shanghai Tianjie Information Technology: A Chinese company that provides DPI-based solutions for network security and traffic analysis.
13. Chinadragon Technology: Another Chinese company specializing in DPI technology for network monitoring, optimization, and security.
14. ThreatBook: While not exclusively focused on DPI, ThreatBook is a Chinese cybersecurity company that may incorporate DPI capabilities in its threat intelligence solutions.
15. Netentsec: A Chinese company specializing in network security solutions, including DPI-based technologies for threat detection and prevention.
16. NSFOCUS: Another Chinese cybersecurity company that offers DPI solutions as part of its network security and monitoring offerings.
17. Venustech: A Chinese cybersecurity company that provides DPI-based solutions for advanced threat detection and network visibility.
18. Topsec: A Chinese cybersecurity company that offers DPI solutions for network security and threat detection.
19. Antiy Labs: Another Chinese company specializing in cybersecurity solutions that may include DPI technology for threat analysis.
20. New H3C Group: A Chinese networking and IT solutions provider that might offer DPI-based technologies as part of its offerings.
21. Venustech: A Chinese cybersecurity company that provides DPI solutions for network security, threat detection, and content filtering.
22. Sangfor Technologies: Another Chinese company offering network security and optimization solutions that might include DPI capabilities.
23. NETIS Systems: A Chinese networking equipment manufacturer that offers DPI technology as part of its network management and security solutions.
24. Nsfocus: A Chinese cybersecurity company that offers DPI solutions for network security, intrusion detection, and threat prevention.
25. Huawei: While mentioned earlier, it's worth noting that Huawei provides DPI technology as part of its networking and security solutions.
26. Thales Trusted Cyber Technologies: A Chinese subsidiary of the French company Thales Group, offering DPI-based solutions for network security.

Other Countries:

1. Sandvine (acquired by Procera Networks): Sandvine, a Canadian company that is now part of Procera Networks, offers DPI-based solutions for network management, traffic optimization, and security.
2. Allot: Allot, an Israeli company, provides DPI technology for network visibility, security, and optimization.
3. Openwave Mobility (part of Enea): Openwave Mobility, which is now part of Enea, offers solutions that utilize DPI for mobile video optimization, subscriber engagement, and security.
4. Symantec (now part of Broadcom): Symantec, a well-known cybersecurity company that is now part of Broadcom, offered DPI-based security solutions.
5. Palo Alto Networks: Palo Alto Networks, though primarily known for its firewall and cybersecurity solutions, incorporates DPI into its products to provide advanced threat detection and prevention.
6. Procera Networks (now part of Sandvine): Procera Networks, based in the United States, is known for its DPI solutions for network intelligence, optimization, and policy enforcement.
7. Bivio Networks: A U.S.-based company specializing in DPI solutions for cybersecurity, network monitoring, and analytics.
8. Cpacket Networks: Another U.S. company offering DPI-based solutions for network visibility, performance monitoring, and security.
9. Deepfield (part of Nokia): Deepfield, acquired by Nokia, provides cloud-based analytics and DPI-based solutions for network visibility and security.
10. Saisei Networks: A U.S. company offering DPI technology for real-time network visibility, control, and traffic management.
11. Netronome: A company with offices in several countries, including the U.S. and India, offering DPI solutions for network appliances and data center security.
12. Telesoft Technologies: A UK-based company specializing in DPI solutions for telecommunications and network optimization.
13. L7 Defense: An Israeli company focusing on real-time DDoS protection and AI-driven application security using DPI technology.
14. Viavi Solutions: A global provider of network testing, monitoring, and assurance solutions that may incorporate DPI capabilities.
15. Cyber adAPT: A U.S.-based company that offers DPI solutions for network security, threat detection, and incident response.
16. NetScout Systems: While mentioned earlier, it's worth noting that NetScout, based in the U.S., provides DPI solutions for network and application performance management.
17. Accedian: A Canadian company that focuses on network performance monitoring and assurance, including DPI-based capabilities.
18. Rohde & Schwarz: A German electronics company that provides DPI solutions for network visibility, monitoring, and security.
19. PacketSled: A U.S.-based company offering DPI technology for network forensics, threat hunting, and incident response.
20. SS8 Networks: A U.S. company specializing in network visibility, communication analytics, and lawful interception using DPI technology.
21. Narus: A U.S.-based company that offers DPI solutions for cybersecurity, traffic analysis, and network monitoring.
22. Wedge Networks: A Canadian company providing DPI-based security solutions for threat prevention and data privacy.
23. Ipoque (part of Rohde & Schwarz): A German company that specializes in DPI solutions for network analytics, optimization, and security.
24. Blue Coat Systems (now part of Symantec): Although mentioned earlier, it's worth noting that Blue Coat, now part of Symantec (Broadcom), offers DPI-based security solutions.
25. Calyptix Security: A U.S.-based company offering DPI technology for network security and monitoring in small and medium-sized businesses.
26. VSS Monitoring (part of NETSCOUT): This U.S. company, now part of NETSCOUT, offers network visibility solutions, including DPI-based capabilities.
27. Cymphonix (now part of Webroot): Cymphonix, acquired by Webroot (a subsidiary of OpenText), provided DPI solutions for network optimization and security.
28. Bivio Networks: Mentioned earlier, this U.S. company specializes in DPI solutions for cybersecurity, network monitoring, and analytics.
29. Ixia (now part of Keysight Technologies): Ixia, now part of Keysight Technologies, offers DPI technology for network testing, security, and visibility.
30. Cisco Systems: While primarily known for networking equipment, Cisco also provides DPI capabilities in some of its products for traffic analysis and security.
31. Allied Telesis: A global networking company that offers DPI-based solutions for network visibility and security.
32. LogRhythm: A U.S. cybersecurity company that offers SIEM (Security Information and Event Management) solutions, which might incorporate DPI for threat detection.
33. Netronome: Mentioned earlier, Netronome provides DPI solutions for network appliances and data center security.
34. NetFort (part of Rapid7): NetFort, now part of Rapid7, offers DPI-based solutions for network monitoring and security.
35. SolarWinds: While known for IT management software, SolarWinds offers DPI capabilities in its network performance and security solutions.
36. Trend Micro: A cybersecurity company that incorporates DPI technology in some of its solutions for network security and threat detection.
37. Netronom: An Irish-American company offering DPI solutions for network acceleration, security, and analytics.
38. Arbor Networks (part of NETSCOUT): Arbor Networks, now part of NETSCOUT, provides DPI technology for network visibility, DDoS protection, and threat mitigation.
39. BlueCat Networks: A Canadian company offering DPI capabilities as part of its DNS and DHCP solutions for network management and security.
40. Cpacket Networks: Mentioned earlier, this U.S. company offers DPI-based solutions for network visibility, performance monitoring, and security.
41. Niometrics: A Singapore-based company specializing in network analytics and DPI technology for various applications, including cybersecurity.
42. Wallarm: A U.S.-based company that incorporates DPI in its application security solutions for protection against web application attacks.
43. Endace: A New Zealand-based company offering DPI technology for network monitoring, forensics, and security.
44. Corero Network Security: A U.S.-based company focusing on DDoS protection and threat detection using DPI technology.
45. Barracuda Networks: While known for various IT security solutions, Barracuda also offers DPI-based capabilities for network protection and threat detection.
46. Flowmon Networks: A Czech company providing DPI-based network monitoring and security solutions.
47. LogPoint: A European company offering SIEM solutions that may incorporate DPI technology for threat detection and incident response.
48. Gigamon: A U.S.-based company offering network visibility solutions, including DPI technology for traffic monitoring and security.
49. Napatech: A Danish company offering DPI solutions for network acceleration, analysis, and security.
50. Flowmon Networks: A European company that specializes in network monitoring and security solutions, including DPI technology.
51. Vectra AI: A U.S.-based company that uses AI and DPI technology for network threat detection and response.
52. Lancope (now part of Cisco): Lancope, acquired by Cisco, provides DPI-based network visibility and security solutions.
53. Anue Systems (now part of Ixia, a Keysight business): Anue Systems, now part of Ixia (Keysight), offers network visibility solutions that include DPI capabilities.
54. Procera Networks (acquired by Sandvine): Mentioned earlier, Procera Networks (now part of Sandvine) offers DPI technology for network intelligence and policy enforcement.
55. Apcon: A U.S.-based company specializing in network visibility solutions, which may incorporate DPI for analysis and monitoring.
56. SS8 Networks: Mentioned earlier, SS8 Networks offers DPI technology for communication analytics and lawful interception.
57. Plixer International: A U.S. company providing network traffic analysis and monitoring solutions, including DPI technology.
58. NETGEAR (acquired Bayshore Networks): NETGEAR, known for networking hardware, acquired Bayshore Networks, which focused on industrial cybersecurity using DPI technology.
59. Netcope Technologies: A European company specializing in FPGA-based network solutions, including DPI technology.
60. Silicom Ltd.: An Israeli company offering networking and data infrastructure solutions, which might include DPI capabilities.
61. Cybera: A U.S.-based company offering DPI solutions for secure SD-WAN and network security in the retail and hospitality industries.
62. Enea Openwave (formerly Openwave Mobility): Mentioned earlier, Enea Openwave provides DPI technology for mobile network optimization and security.
63. NetFort (part of Rapid7): Reiterated here, NetFort, now part of Rapid7, offers DPI-based solutions for network monitoring and security.
64. InfoVista: A French company providing network performance and application visibility solutions, which may incorporate DPI technology.
65. SonicWall: A U.S.-based company offering DPI capabilities in its network security appliances for threat detection and prevention.
66. Nubeva: A Canadian company specializing in decryption technology and DPI solutions for cloud visibility and security.
67. Gigamon: Mentioned earlier, Gigamon offers network visibility solutions, including DPI technology for traffic monitoring and security.
68. ntop: An Italian company that develops network traffic analysis tools, including DPI-based solutions.
69. Extrahop (acquired by Arista Networks): Extrahop, now part of Arista Networks, provides network detection and response solutions using DPI technology.
70. Penten: An Australian company that offers DPI-based solutions for secure wireless communications and network protection.
71. Qosmos (part of Enea): Reiterated here, Qosmos, now part of Enea, offers DPI technology for network analytics and cybersecurity.
72. Nominum (now part of Akamai Technologies): Nominum, acquired by Akamai, provided DNS and network security solutions that incorporated DPI capabilities.
73. CounterFlow AI: A U.S.-based company that utilizes DPI and machine learning for network traffic analysis and cybersecurity.
74. NetFortris: A U.S. company offering network security and communication solutions that may include DPI technology.
75. Palo Alto Networks: Reiterated here, Palo Alto Networks incorporates DPI in its firewall solutions for advanced threat detection and prevention.
76. FireEye: A U.S. cybersecurity company that uses DPI technology for threat intelligence and detection.
77. Cyber adAPT: Mentioned earlier, Cyber adAPT offers DPI solutions for network security, threat detection, and incident response.
78. Lastline (acquired by VMware): Lastline, acquired by VMware, provided DPI-based solutions for advanced threat detection and network security.
79. Darktrace: A U.K.-based company specializing in AI-driven network security that might incorporate DPI capabilities.
80. Fidelis Cybersecurity: A U.S. company offering DPI technology for threat detection, data loss prevention, and network visibility.
81. Vectra AI: Mentioned earlier, Vectra AI uses AI and DPI technology for network threat detection and response.
82. TitanHQ: An Irish company that provides DPI-based solutions for email and web security.
83. Flowmon Networks: Reiterated here, Flowmon Networks offers DPI-based network monitoring and security solutions.