[Connectivity] Consistent packet loss with big spikes in the afternoon

Required Information: Location: Grand Island, FL Modem: Motorola SURFBoard SB 6121 (latest firmware) Router: TPLINK TL-WDR4300 (running DDWRT, latest release) Connection: 50/10mbps (Blast!) My Problem Since around November 2013 I’ve been experiencing packet loss, around 1-5%. My connection speed and ping (on average) are completely fine. Its odd - most of the time there is 0 packet loss. At seemingly random times, my connection will begin dropping packets for maybe 1 second at roughly 20-30 second intervals. It will just spike randomly over time - this lasts for several hours. If I was simply browsing the internet, using Facebook or searching for things, I’d never notice it. However, it affects anything real-time drastically. If I use VOIP services, other users hear my voice cut out and scramble every few seconds. Real-time games lag and stutter due to the desyncing issues caused by packet loss. I ran a smokeping on my address for some visuals of the problem: [att=1] Here is a closer look at a specific instance of this packet loss. You can really see the packet loss over the last 3 hours. In the lower graph, you can see how for most of the day, my connection was great, but then packet loss shot up around 19:00: [att=2] I understand that ICMP echo pings are sent with a low priority and may be dropped, but these graphs fit the exact timelines that I’m experiencing problems with real-time internet applications. I would also like to point out that these images are fairly standard. Smokepings consistently show my connection with an average of 1-10% packet loss depending on the time and location of the other server. Here is a snapshot of my modem's power levels, signals and codewords status. Its my understanding that my power levels and signals are well within spec. I'm not sure if my "total uncorrectable codewords" ratio is normal, though: [att=3] What has been done so far? I’ve lost track of how many times I’ve contact Comcast support to address the issue. The just send a “reset signal” and tell me that some packet loss is normal. I’ve had 3 to 4 technicians visit my home to help track down the problem. I’ve had some fittings on my coaxial jacks replaced (I was told there was a very small amount of interference being caused by old, cheap fittings). They say the signal is excellent and within spec. There is very little interference on the line. However, there is no packet loss when the techs visited, so they can’t really do much else but tell me it looks fine. The technicians insisted that my modem was to blame, so I replaced it and the router. I’m currently using a Motorola SURFBoard SB 6121. This is a DOCSIS 3.0 modem with support for a connection that is more than twice as fast as mine. My router is a TPLINK TL-WDR4300 flashed with the latest version of DD-WRT. All computers connected to this router are hard lined with brand new CAT5. I’d like to point out that the packet loss persists even when I directly connect my modem to a computer. Any suggestions? I'll gladly provide any other information you might need. Edit: It seems that most of my issue is with outbound traffic. For example, I can be chatting on Skype and I'll hear all the participants in the call just fine, but when I speak to them my voice cuts out randomly and I'm difficult to understand due to the packet loss. I'm not 100% sure if this is the case, but the issue does seem to be much more prevalent with outgoing traffic.