Posts Tagged ‘networking’

Aztech Homeplug 85Mbps HL105E Review

// February 26th, 2010 // No Comments » // Technical Know-It-All

Like all my reviews, I generally try not to cover too much of the technical specifications. Chances are, the fact that you are reading this, you would have probably covered the tech specs on the vendors website and looking for a users view on it.

So, a quick brief on the problem statement that I have and why my impetus for this product.

Recently, I was given a free gift (which happens to be small form factor PC, that works very well as a HTPC) from Starhub for renewing my SCV connection. I decided to deploy this in my bedroom as an extension for my Media Collection which is in the hall (running off my Synology NAS). The problem with this setup is that, the wireless connectivity between the bedroom and the hall is extremely week making video streaming unwatchable. In order for this to work, I needed a wired connection but I wasn’t ready to start running Ethernet cables all over the apartment.

In comes the Homeplug! I have always wanted to give it a try but have always been suss about the technology and how it works. I did a lot of read up on it in the past. The discussion of using electrical power lines to run data traffic, is usually something like a big taboo in the datacentre world. Interference, performance, data privacy and integrity usually the main concerns.

So, setting it up was somewhat a breeze. Just plug your network cable to the Homeplug and the other end to your router/switch/device and plug it into any power point in your home. Optionally you would want to set it up as a Private network cause you’d never know if your power lines at home is linked in someways to your neighbour’s. If it was the case, your neighbour can easily get a Homeplug and plug it into their power point, and you guys will be looking at data privacy being compromised. However, this can only be setup by installing the configuration software on Windows. (nothing for Mac)

While it is recommended that you setup a “Private Network”, by default it is set to “Homeplug Network” which is public. So if you choose to not configure it, just skip all of the above and plug in the cable and you are ready to go.

The top speed for the Homeplug is rated for 85Mbps which is a little short of the traditional 100Mbps. For the layman, usually when we talk 100Mbps, the max throughput would probably be rated at around ~75-80Mbps  given the overheads in the IP Protocol. So when the same is applied to the Homeplugs, the max throughput expected is around ~60-65Mbps.

First bandwidth test was to stream a HD mkv file from the NAS on to the HTPC (running Windows 7). The video was very jerky and barely watchable. I then ran streaming for a 700+MB avi file. It was a little better but still choppy at times. For a moment there, it seemed that 65Mbps was not cutting it for video streaming. This doesn’t make sense given that I was able to stream HD movies wirelessly on my Macbook while sitting next to my wireless router where bandwidth is way less than 100Mbps. At that point, it seemed like a link stability issue could be the cause. I ran a latency test between the routers and the Homeplug units and they were all ~2ms which somewhat seem to suggest that the link hasn’t got any issues.

To cut the story short, in the end it was Windows 7 that was the culprit because of a new feature implemented during the Vista deployment called “Network Auto Tuning”. Instead of making things better it made it worst. Once disabled, everything worked like how a wired network should and even 4GB mkv’s were streaming effortlessly.

The bad thing about the Homeplug is that it will consume 1 power point to itself given the size of the unit. I tried running it on a multi-point power distribution unit and also a multi-adapter 3-point plug, and I must say that the performance was still good. Alternatively you can always consider the HL109EP that allows the point to we reused (which is double the price of this unit). One thing I did noticed as well is that the Homeplugs doesn’t heat up a whole lot even though its turned on 24/7 which can be a good thing for some.

In summary, I would recommend this product for those who do not require an extremely high speed network at home. It works well for video streaming, music streaming, Internet and the occasional file transfers. But if you are planning to run high bandwidth applications like video editing to a NAS unit or something along those lines, you would probably be better off running a physical ethernet cable. Also, for those who are non-tech-savvy, it doesn’t get any easier to setup your home network with this.

The Buzz About FCoE and CEE

// February 26th, 2010 // No Comments » // Technical Know-It-All

The new buzzword these days in the Storage / Networking space is FCoE (fiber channel over ethernet) and CEE (converged enhanced ethernet). For those who are unfamiliar with the whole concept, in layman terms, it is a convergence of the traditional TCP/IP networks and traditional SAN networks into a single giant network.

While it is ideal from a C-Level perspective to streamline processes, reduce costs, go green and try doing more with less, at the technical level, it is never as easy as the vendors make it seem. Many industry experts have claimed that this new protocol will eventually replace the ever resilient FC Protocol and Ethernet. The jist of it is that, everything that has to do with “networking” will run on this newly improved protocol.

While this “could” be true, here are some points to ponder upon before taking the leap of faith to run your entire production systems on CEE and FCoE.

1. TCP/IP has never been known to be the most secure protocol (before I get flamed by the networking experts, it can potentially be secured with the right amount of tweaking). Compared to FC, while some may disagree, it is more secure in some ways (for starters, given that not every laptop will have an FC port to begin with, but having said that, more often than not SAN administrators take this for granted). By merging the 2 protocols together, suddenly we have a scenario where security might now be a concern to the traditional SAN guys.

2. Usually in large environments there is usually a Storage Team and Network Team. With the convergence, a discussion of job roles would probably emerge, and potentially job cuts (fingers crossed).

3. Standards. Currently, many of the protocols/standard are still very much in the review stage with IETF, T11 and the lot. Ethernet is stable today after many years of revision while CEE will take some time before reaching that level of maturity.

4. Physical infrastructures such as cabling are probably not ready today for a complete deployment. Many are still running cabling works that are barely rated for 1Gbit, let alone the 10-40Gbit as promised by CEE/FCoE. Also, existing Ethernet switches and FC switches are not meant to run this new protocol. Slowly and surely, vendors are releasing firmware updates to enable them to support the protocol in the legacy units, but having said that, the additional overheads of the protocol was never meant to run on existing hardware, so we might never know if it will be able to handle it. Newly released FCoE/CEE ready devices are slowly coming to market and today cost quite a fair bit.

Obviously, my little list above is not all conclusive, but my 2 cents of what I would probably be concerned about when thinking of rolling it out.

So in summary, I am not saying that CEE/FCoE is doomed for failure but maybe, just maybe, it is still too early for it to be totally viable in a full fledge production environment. I do believe that CEE/FCoE will take off and be a prominent protocol some day. Having said that I don’t think it will oust or replace traditional FC and Ethernet anytime soon as some major vendors are suggesting. It takes more than lowering cost and bandwidth to achieve total protocol dominance.

Just ask iSCSI and Infiniband. :)

Graphical Network Simulator 3, GNS3 Review

// January 8th, 2010 // No Comments » // Technical Know-It-All

A few weeks back, I was tasked to skill up on IP at work. It seems like ages since I completed my Cisco Training Academy, so I decided the easiest way to get back into it is through Cisco simulators out there. In all honesty, I would much prefer having the physical boxes to play with but I have sold them all when I moved to Singapore 2 years back.

The popular simulators out there would be Boson and RouterSim, which (I honestly think) is fairly buggy at best. The problem with simulators like Boson & RS are manly due to the fact that it is usually re-engineered code made to look and feel like Cisco’s IOS. Not all commands are available (though visible on the “?”, doesn’t mean it’s usable), abbreviated commands (sh run, cop run st, etc.) doesn’t always work, output might or might not be what is expected and the list goes on. It’s not as bad as it sounds, because people do get away passing CCNA’s and CCNP’s from it. (Maybe it’s just me).

Anyway, I came across GNS3 as an open source alternative to the other “paid” sims out there. From experience, open source goodies are generally difficult to setup at best. But I was truly surprised with the setup for GNS on Windows. Unfortunately, I can’t say the same for the Mac OSX though. Still struggling to get it to work on my Mac.

GNS3 Screenshot

GNS is basically a GUI version of Dynamips if you are truly interested in what’s happening in the backend. (I’m not, so no elaborating here :) )

Like all things FREE, there is always a catch! The catch with GNS is that it requires a Cisco IOS binary file in order to work and it only supports router codes (no switches). If you really really need a switch, you can potentially configure a 36xx and put in an Ethernet card slot to make it into a switch. I remember seeing a tutorial on this on the GNS Documentation site. Officially, you have to be a Cisco Partner or Customer to be able to download these images, but surely I’m sure you can find some floating around on the web.

So how does it work?

What it actually does is emulate a Cisco Router with the original IOS on your workstation. It’s pretty much VmWare for Cisco Routers if you like. Once you sort out the IOS installation and tell it where Dynamips (which is installed as part of the GNS3 package) is located, you are ready to go. Building the virtual network if as simple as drawing a Visio diagram. You can also add in additional WIC’s or line cards, and RAM (just like VmWare can for Servers). And the best part… no limitation on CLI and output. What you see if what you get on the real thing! Same IOS code like the real deal, only difference its that you don’t have the equipment physically. If y0u can get hold of Cisco 36xx series router binaries, you can potentially setup a virtual lab to do your CCIE (a little far fetch, but not totally impossible). Based on the options available, the latest version is capable of taking Cisco PIX & ASA binaries, and JunOS. I have yet to try it because I do not have access to any of those code. Maybe you guys can let me know when you try it out.

So if you are an aspiring CCNA or CCNP or even CCIE on a budget, give this a go.

www.gns3.net

Are you trying to port forward “http” on Starhub?

// December 30th, 2009 // No Comments » // Singapore, Technical Know-It-All

Starhub or Singtel? Hmmm....

Starhub or Singtel? Hmmm....

Just incase you are wondering why you can’t setup your router to forward port 80 (http), this is because Starhub has blocked users from setting up their own web servers using MaxOnline Home Broadband! What a rip off!

Mac OSX Time Machine Review

// December 30th, 2009 // No Comments » // Technical Know-It-All

Here is a quick review about Time Machine.

I have been using the Mac since the Tiger days and have always used rsync as a way to backup my files. Obviously with the recent OSX’s, Time Machine has been thrown in to the mix as a form of “backup”/”archival” utility. I finally decided to take the plunge and give it a go.

My setup was as such…
Directly connecting my Macbook Pro to the switch and running Time Machine backups to the NAS device on 100Base. (for the initial copy, and wireless for incrementals in the future)

The initial copy for 200GB took “ages”. I think it took somewhere between 10-12hours. Kinda lost track after a while.

Once the initial sync is done, its all hunky dory. For the new few days, I managed to do incremental backups over wireless effortlessly, and for a moment there, it’s the best thing since sliced bread.

As my job requires me to travel quite a bit, I don’t always get to sync it everynight. So it is pretty common that I have quite a good amount of changed files. It happened recently while I was away for a week and had to sync about 2GB over wireless. Mid-way through the sync, I stopped it and wanted to sync it up again later when I had the time.

When I tried the next time, Time Machine kept complaining it can’t sync and the removable drive was unreadable. After going through the web looking for a solution (which includes checking it for errors, mounting and remounting and etc), I chanced upon an article that explained why the backups on Time Machine is easily corrupted.

Apple usually recommends using Time Machine with Time Capsule. Apparently, the Time Capsule has more buffering cache to help it perform backups via wireless connections while 3rd party NAS are just not built that way. Having said that, even if you did use Time Capsule, it is also no guarantee that backups will never corrupt over wireless.

I knew it was too good to be true.

So for now, I have reverted back to wired connections for backups and I am currently trialling Carbon Copy Cloner. Will let you guys know soon!

This is the Time Machine!

This is the Time Machine!

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