APC USB Mobile Power Pack

APC USB Mobile Power Pack (UPB10)Recently I ordered an APC USB Mobile Power Pack (UPB10) since I found it for a good price (< $30) and was going to be traveling. I had considered it before for my older Sony CLIÉ whose battery was starting to suffer but held off. Now having an iPhone this seemed like a good investment. While traveling this weekend I got a chance to give it a real test.

The great thing about this device is that it’s generic. Any device that can be powered or charged via USB can be charged with this. It simply provides power over USB, nothing more. You use your regular USB sync/charging cables. iPhone, iPod, PDA, bluetooth headset, most cell phones, all can be charged this way. That’s much better than an accessory that only charges a certain device. The downside is you need to have the cable handy, which for me isn’t a big deal since the iPhone power adapter is USB based as well. Being able to charge all sorts of gadgets makes this a pretty handy thing to have.

The unit itself is dead simple. It’s a little smaller than an iPhone, and surprisingly light. Two ports, a USB Type A, and USB Mini-B on the top, and a status indicator and button on the front. To charge use the power adapter, which is sufficiently compact though could be better which interfaces with the USB Mini-B port. It takes about 3.5hrs to charge. To charge your device just use the USB cord you normally use and plug it into the USB Type A port. The power pack itself doesn’t come with a cable to charge. Press the indicator button to see how much of a charge is left. That’s about all there is to the device.

After not charging for a while, and watching a movie on the plane, my battery was getting pretty low. I decided to hook up the APC USB Mobile Power Pack and continue watching video. After about an hour or so (while watching more video), my battery was fully charged and the Power Pack still has about 75% of it’s charge remaining. Not bad at all. Rather than land with a drained battery as you typically do with gadgets, I had a full battery.

It’s not a bad device for a pretty reasonable price. Some airplanes have power outlets outside of first class, though may cost a little extra for those seats. In many cases they use EmPower® or a DC “cigarette lighter” port which require their respective adapters. This runs about the same cost as an adapter, and removes the requirement of being on a plane, in a seat that has a outlet handy. If you need to power a laptop, your going to need an outlet. For a mobile device, this is a much better solution.

Network Perils

It’s been a week of networking pain. For the past few weeks Comcast has been using a low DHCP lease time. 30 minutes to be exact. This is typical of when they are doing network upgrades/repairs and is what a normal network administrator does. It’s similar to lowering the TTL for DNS.

Renewing the DHCP lease is normally a pretty transparent process, but this time around it’s been causing network connections to drop. While this process is relatively quick, it still resulted in a brief network outage that would kill connections. Occasionally it created a spike when things came back online, which made it feel even longer due to the resulting lag.

No configurations have changed in a long time other than a firmware upgrade a few months ago. Strange I thought. Why is it insisting on on loosing the IP and rediscovering, rather than just renewing? I let it go for a few days hoping Comcast’s low DHCP lease time would be temporary. After 2 weeks I decided to dig deeper.

After a few emails with Motorola’s tech support (Motorola bought Netopia in 2007) they came to the conclusion that the renew-lease ACK packet wasn’t reaching the router. They suspected the firewall wasn’t allowing it to pass, as a result it was dropping the IP, and requesting it again from the DHCP server. They suggested opening up UDP/67 and UDP/68 on the firewall. This seems to resolve the problem. I’m still seeing the lease drop at about 1:00 AM for the past 2 nights, but that’s really a low priority issue and may indeed be on Comcast’s end. It’s possible the router was renewing the hard way every 24-72 hours for a few months, but I know Comcast’s DHCP lease time has been lowered before and the router didn’t exhibit this behavior. Perhaps the firmware upgrade changed the firewalls behavior? I don’t recall that in the docs. Regardless, it’s fixed.

Now today, the UPS for the router, modem and file server’s battery died. Yet another pain. I was able to swap the battery with a similar model UPS from another computer for now. I can deal with that other computer later.

Now maybe I can take my networking hat off for a little while.