List of 71 Bad Cable Modems You Should Avoid Buying [Do Not Buy]

A bad modem can severely restrict your internet surfing and online gaming experience. However, you cannot determine them just by looking at the specs. In most cases, they’ll will look completely fine until you make the purchase.

If the modem starts throttling the internet speeds, shows increased jitters, and high latency, it could be a faulty modem. That said, even the internet provider can cause these issues and therefore, it is necessary to run detailed diagnostics before blaming the equipment.

Thanks to the network security experts and forum users, who tests a lot of internet equipment. It is because of them, that we’ve finally found out the bad modems which you should avoid. Also, in some cases, the modem manufacturers have taken steps towards the issues and claim to have resolved the problems, but why risk it, when there are plenty of models available on the internet.

List Bad Modems To Avoid in 2020

Here is the complete list of faulty modems that we must refrain from. While the primary focus was on bad modems featuring the Puma 6 chipsets, we also included the ones with Intel Puma 7 CPUs.

1. ARRIS CM3200
2. ARRIS DG1660
3. ARRIS DG1670
4. ARRIS DG2460
5. ARRIS DG2470
6. ARRIS DG3260
7. ARRIS DG3270
8. ARRIS DG3450
9. ARRIS SBG10
10. ARRIS SB6190
11. ARRIS SBG6950AC2
12. ARRIS SBG7400AC2
13. ARRIS SBG7580AC
14. ARRIS SBG7600AC2
15. ARRIS SBG8300
16. ARRIS SBV2402
17. ARRIS SBV3202
18. ARRIS SVG2482AC
19. ARRIS T25
20. ARRIS TG1652
21. ARRIS TG1662
22. ARRIS TG1672
23. ARRIS TG1682
24. ARRIS TG2472
25. ARRIS TG3452
26. ARRIS TM1602
27. ARRIS TM3402
28. ASUS CM-32
29. Hitron CDA3
30. Hitron CDA3-35
31. Hitron CGN3
32. Hitron CGNM-2250
33. Hitron (CGNM) CGNM-2252
34. Hitron CGNVM-2559
35. Hitron CGNM-3550
36. Hitron CGNM-3552
37. Hitron CGNVM-3580
38. Hitron CGNVM-3582
39. Hitron CGNVM-3589
40. Hitron CODA-45
41. Hitron CODA-4502
42. Hitron CODA-4580
43. Hitron CODA-4582
44. Hitron CODA-4589
45. Hitron CODA-46
46. Hitron CODA-4602
47. Hitron CODA-4680
48. Hitron CODA-4682
49. Hitron CODA-4689
50. Hitron CODA-47
51. Hitron CODA-4702
52. Hitron CODA-4780
53. Hitron CODA-4782
54. Hitron CODA-4789
55. Linksys CG6350
56. Linksys CG7500
57. Linksys CM3016
58. Linksys CM3024
59. NETGEAR C6300
60. NETGEAR C6300v2
61. NETGEAR C6300BD
62. NETGEAR CBR40
63. NETGEAR CM700
64. Cisco DPC3848V
65. Cisco DPC3941B / DPC3941T  (commonly, Comcast Xfinity XB3)
66. Cisco DPC3939
67. TP-Link CR7000
68. Compal CH7465-LG / Arris TG2492LG (commonly, Virgin Media Hub 3)
69. Samsung Home Media Server
70. Super Hub 3 (Arris TG2492LG)  (commonly, Virgin Media)
71. Telstra Gateway Max (Netgear AC1900 / C6300) (Australia)

How to Identify a Bad Modem?

Troubleshooting the modem can help you intercept the effectiveness of the same. There are quite a few techniques to check whether the modem is defective or not.

• Performing a Speedtest is a good way to check for latency followed by the jitter test. Perform it using: Speedtest by Ookla / Cloudflare Speed test
• Ping test can be used for concerns related to packet dropping.
• Intel Puma 6 chipsets: It is advisable to avoid any modem that has the Intel Puma 6 chipset in it.

However, few brands do not feature logos on the package. For that, you can always refer to the featured list at the bottom for enlisting the modems to avoid. 

Matthew M BRACEY, APPROVEDMODEMS.ORG

Modems with Puma 6 Chipsets

Modems featuring Intel Puma 6 chipsets are known to experience speed, jitter, and latency related issues. In simpler terms, they take a lot of time when it comes to processing network packets. 

Initially, it was the gamers identifying this issue, upon encountering lags. Eventually, what was presumed to be a minor hardware issue, turned into a big-discovering lawsuit!

The Bugs

Intel Puma 6 chipsets had bugs, responsible for throttling speed of operations. Moreover, the bugs even opened up avenues for pranks. It was possible for the attackers to determine the low-bandwidth streams and eventually force the modem offline. 

The Puma 6 Bug also makes way for connection lags courtesy of smaller payloads. Not just that, these bugs were also discovered in Puma 5 and Puma 7 chipsets. 

Vulnerabilities

The mentioned bugs made the Puma 6 modems are prone to several performance-hindering vulnerabilities. The major one under consideration was the performance loss. The worst case scenario involved packet exhaustion right at the inception stage.

In addition to that, the vulnerabilities also made way for spike in network latency. In most cases, increased latency made way for sub-par gaming and interactive performances. Moreover, in a few cases, the attackers could even blow-off the adjoining hardware.

From a more technical standpoint, the associated vulnerabilities made sure that processing network packets was a tediously slow process. The CPU side-tracked the essential tasks and allow the pranksters to take up all the resources belonging to the SoC. While the optimal latency range is 20ms-40ms, these modems even experienced something in the ballpark of 200ms. 

Rogue tasks ate up the speeds and resources allocated for the basic networking activities. Moreover, almost 6 percent drop in either IPV4 or even IPV6 packets were encountered. The x86 Processor couldn’t handle high-maintenance tasks like gaming and hogged up the processor; thereby spoiling gaming and other online activities. 

Vulnerabilities included driving the modem offline via low-bandwidth streams. In certain cases, even one percent of the requisite bandwidth resulted in modem crash. 

However, in order to exploit these vulnerabilities, the attacker must know the IP of the concerned user. That said, other issues involving jitters and latency persisted even without attackers running foul. 

Not just the more demanding activities but even basic online interactions get thwarted due to the existing vulnerabilities. 

The Lawsuit

Defective Puma 6 chipsets in select modems eventually led to a class-action lawsuit, filed by the consumers. At present, Schubert Jonckheer & Kolbe LLP is the law firm investigating the matter and fighting the class-action on behalf of the ill-fated customers.

To start with, the lawsuit originally concerned Arris International as initially it was there modems which showed signs of defects. With customers experiencing spike in latency and degraded connections, the lawsuit was quite an obvious choice. 

Both Arris and Puma accepted the issues and defects but did nothing in regard to solving the issue. Therefore, as part of the remedial plan, authorities instructed the company to refund the full modem value, in case the user ends up getting a defective piece. 

The concerned law firm eventually moved onto other manufacturers selling modems containing the Puma 6 SoCs. The companies under the scanner were Linksys, Hitron, Cisco, and Netgear. 

Users, who have purchased a defective modem, based on the vulnerabilities and bugs listed above in the discussion, can file issues separately with the law firm. This way they become eligible for updates and even compensation based on the culmination of the class-action lawsuit. 

The common theme of the class-action is based on the violation of the consumer protection standards in the US. 

Why Should You Avoid Bad Modems?

There are quite a few reasons why you must refrain from purchasing bad modems. Here are some of the threats that come along with the faulty Puma 6 modems.

1. DDoS Threat: Modems sheltering the Puma chipsets, including Puma 5, Puma 6 and even Puma 7 are prone to DDoS attacks. If your IP address is known, the attacker can tap into the network with ease. Eventually, you might start experiencing timeouts and resource depletion. Do you want it?
2. Increased Latency: The bad modems with Puma chipsets in them increase network latency and negatively impact online activities. Increased latency means that gaming and other web-based activities take longer than expected as the modem keeps dropping the network packets. 
3. Modems featuring Puma chipsets can cause almost 6 percent drop in network packets, leading to the highest possible network latency of 200ms. 
4. Higher Jitters: Jitter is determined by the spread of latency across timeframes. Puma 6 chipsets make sure that the networking latency varies from 2 seconds to even 0.001 second or even more.

Therefore, besides slowing down the speeds, the interactive experience over the internet is frustrating and completely random. Jitter is one aspect that affect game-playing the most. 

Are there any Fixes to The PUMA 6 Chipset Issue?

To start with Arris started the initiative by resorting to the Broadcom chipsets instead the Intel-powered ones, in select devices. 

Another strategy used by certain modem manufacturers includes setting up a compatible firmware onto the gadgets. This approach includes blocking the slow and jittery sequence of packets that hinder the performances. However, companies are rolling out the firmware updates as a very slow pace. 

Lastly, the best fix is to avoid the modems that we have listed in this post!

Matthew M BRACEY

The Verdict

A faulty modem can hinder your online experience while making you prone to threats and vulnerabilities. Not just that, there are several safety concerns to account for.

While only modems with Puma 6 chipsets showcased issues, there are updates the even the certain Puma 7 devices crashed courtesy of the existing Intel-specific issues or an entirely different bug. 

Most importantly, Intel has decided to exit the modem business while focussing all the efforts towards improving network infrastructure. 

Therefore, it is necessary to keep a close eye on the mentioned list of defective modems and stay away from the featured models while making the purchase.