Configuring QoS in Cisco IOS

I'm back! Today I'm posting a how-to on QoS (Quality of Service) configuration on Cisco routers and switches.

QoS is a valuable tool whenever you have different types of traffic arriving at a router where they'll need to be aggregated and sent out over a single link like a WAN connection. Some types of data and applications require traffic to be handled with as little latency and jitter as possible; VOIP is a prime example of this, as well as Citrix, RDP, and anything else that involves streaming audio and video.

The reason this is important is because as a traffic arrives in a router, it gets sent into a processing queue in the router based upon the order in which the packet was received. After routing decisions are made, this traffic is sent into an input queue for the WAN interface in preparation of being sent out over the WAN link.

Traffic passes from this input queue into the transmit ring, a hardware output queue. If this queue fills up during a period of high traffic congestion, additional traffic arriving to the interface is queued in the software output queue, where it waits on room in the transmit ring to become available. If the software output queue (usually just called the output queue) gets filled up and traffic is still arriving at the interface, the interface has to start dropping packets. These are recorded as "Output drops" when you do a show interface command.

If this happens, critical data can be dropped, or voice traffic can be delayed while it sits in the output queue with less important traffic in front of it. Even if the voice traffic is successfully delivered, the delays can cause stuttering and poor quality on the call.

QoS prevents problems like these by guaranteeing bandwidth to critical data and preventing that traffic from being dropped if the circuit becomes congested. It can also be configured to prioritize certain types of traffic over others in terms of the order they are transmitted, to ensure time-sensitive traffic is transmitted as quickly as possible.

Hit the jump and we'll look at this in detail!

Dreams made reality

Okay, so I'm well overdue for a check-in. A lot has happened since my last post so I'll try to fill in the gaps.

First, I got a new job. In my dream field, networking. I'm now an enterprise WAN data technician working in a NOC!

Tomorrow will be my last day of nearly 2 months of training (I was hired in the 3rd week of November). I was initially trained in Facilities, which gave me some background in telephony and TDM circuits (T1, T3, etc). I'm now able to test T1s for errors, troubleshoot phone issues on PRIs and CAS lines, and refer tickets on the local loop out to carriers for resolution.

During my training in Facilities, the company transitioned to ownership by another carrier, and I believe I was likely the last employee hired under the original company. I even played a game of Foosball with the Fortune 1000 CEO on the evening of the last day he owned the company, losing by a few points, undoubtedly due to the few pints of lager I'd had by that point. :p

After about 5 weeks came the good stuff: data training. I was trained on QoS, MPLS (multilinks), VLANs and Trunking, Metro Ethernet, Multilink Frame Relay, BGP, ACLs, subnetting and more. I already have a decent understanding of the LAN side of networking so some of the stuff like Metro E was pretty easy to understand, and I already knew subnetting, ACLs and VLANs pretty well.

On top of everything I've learned, I'm also looking at a reasonable bump in pay as well, which has me preparing a proposal to Lynn as well as a reasonable likelihood of owning a house in my future, especially as my family has one that they're willing to sell me (in one of the best neighborhoods and school districts in the country!)

I've also been offered a job writing articles on smartphones for a tech blog startup, and while I've written a few articles (and will not disclose the website here just yet), I've been so busy with my new job and the holidays that I've not written enough to earn any pay.

Lastly, I also won the Christmas Grand Prize over at AndroidAndMe.com's 25-Days-Of-Tegra giveaway! I won a Transformer Prime tablet with keyboard dock, a Sonos sound system, and a Kindle Fire! The stuff hasn't come yet (and has been a daily reminder of how impatient I am) but I'm very excited to see it come. It's possible the Transformer Prime has been delayed by ASUS' announcement that they're releasing a second-edition model that will resolve some of the issues people have had with GPS and WiFi performance due to the metal back of the tablet.

In closing, I'll try to keep up on my blog, maybe post a few Cisco-oriented articles, but I expect my life is going to continue in high gear for the next several months while I continue to focus on learning everything I can about WAN networking, get a ring for my girlfriend, and work on buying the house.

After years of struggle, I'm finally seeing my goals achieved... and I couldn't be happier!

Fun with Tasker Part II: Covert mugshots!

Okay Blog, I've been neglecting you. Today, I'll outline a neat little trick once again using the amazing automation tool, Tasker.

First, I've an admission to make. My phone doesn't use one of those coded lockscreens. There's a couple reasons for this... I don't have time to deal with it, and it's far too easy to get around those screens by looking at a screen at a shallow angle and seeing where the fingerprints are.

That said, my phone hardly is lacking in the security department. I've written a few pretty involved scripts in Tasker that will, when I text the phone a secret phrase, turn my phone into an information-gathering powerhouse.

Specifically in this post I'm going to describe how I can covertly and remotely grab photos from the front and rear cameras on my phone as well as see the ugly mug of the last person who unlocked my screen, and have those photos quietly emailed to me. This can be an awesome tool if your phone is stolen or if you just want to know who the last person to unlock your screen was.

Let's get started!

Still alive!

I'm still here! Work has been taking up a lot of my time as of late, and I've resumed my Cisco studies. My goal is to be able to take the CCNA exam at the end of August. I'm already well versed in ICND1 (which I'm halfway through re-reviewing now) and I'll commit 3 weeks to studying ICND2 before taking the CCNA exam.

Helping motivate me is my friend Bob, who recently went to work for Google. He's studying for the CCNA too, and we're meeting weekly via Google+'s new Hangout system to discuss our progress.

For those of you still interested in Android phone news, check out this article by AnandTech:

http://www.anandtech.com/show/4551/motorola-droid-3-review-third-times-a-charm

As usual for AnandTech, the review is excellent.

The Android Invasion: My impressions of our new Neato XV-11 robotic vacuum

So, my girlfriend has always been saying that the one thing she wishes she had more of is time. She joked around with me several months back about getting a Roomba to make life a little easier for us, and my curiosity was piqued.

Tomorrow is her birthday, so I went all-out and bought a Neato XV-11 robotic vacuum. I've only played with it for about an hour, so consider this more of a "hands-on" review than anything thorough.

First, important "good boyfriend" tip. Never get your girlfriend something that you're even more excited about getting than she is, even if she said she wanted it. She certainly likes it, but I've definitely been given the "oh I see why you got it" treatment. I really did get it for her because I wanted to see her smile as a machine cleaned the house for her, but since it benefits the both of us, perhaps it wasn't exactly the best birthday present choice. Duly noted!

Read on past the break for my review.

The Empire Strikes Back: Qualcomm's Dual-Core benchmarked

AnandTech has gotten their hands on a Qualcomm prototype, brought it home and benchmarked it. The dual-core, 1.5 Ghz development phone runs at max clock speeds and isn't a perfect example of what we'll see in production handsets, but it does give a taste of what Qualcomm has in store for the mobile industry later this year, and the results are impressive. This unit also packs a next-gen Adreno 220 GPU and is optimized for graphics performance.

Take a look!
http://www.anandtech.com/show/4243/dual-core-snapdragon-gpu-performance-1-5-ghz-msm8660-adreno-220-benchmarks

The Necromancer

The title of this blog post also happens to be the name of the book I'm reading. Perhaps I've just been inspired to do a little necromancy of my own, but with less cadavers and more circuit board.

I'll explain; let's start with the fact that something's been bugging me. My desktop PC does not have a discreet GPU (video card).

You might be thinking, "WTF, and you call yourself an electronics freak?!" Well, you've got me there, but I do have reasons. One primary reason is that I'm not a gamer anymore. I do almost everything on this laptop nowadays, and I only took my desktop out of storage a few weeks ago so that I could get a decent VM box running in the basement next to my HTPC and my Cisco lab hardware.

However, my integrated GPU (despite it being a reasonably beefy AMD HD 3200) just ain't cuttin' it for some of the video processing and RemoteFX stuff I'd like to mess around with.

Fortunately, I have an NVIDIA 8800 GTS in a static bag that should do what I need it to do. Unfortunately, it's going to take a little more than me popping this sucker into my PC to get it running.

Problem #1: The graphics card does not have an enclosure for the heat sink; the fan cannot circulate air to keep it cool.

Problem #2: It's damaged goods. (Okay, I lied, the card isn't entirely dead. But someone who brings sick people back to life is a doctor, and that's a lot less fun than being a Necromancer!) It displays bands of pixels vertically across the screen that are visible during the boot process, which means it's a hardware issue, not a driver problem. Additionally, it usually won't boot into Windows, causing the system to hang when the operating system is starting up. On the rare chance it does make the boot into Windows, graphics are horribly distorted.

So, I'm screwed, right? Hell no! I wouldn't pass up an opportunity like this! Read on to see how I got this old workhorse running again.

Smartbench 2011: your multi-core benchmark

Smartbench 2011 is now on the Android market! I encourage everyone who likes to benchmark to download and use this excellent tool. (Insert disclaimer: benchmarks are benchmarks, nothing more; they should not be used as proof for anything.)

It's the successor to Smartbench 2010, which I've done a lot of testing with on behalf of it's developer, Acei, the admin over at www.smartphonebenchmarks.com. Smartbench 2010 demonstrated itself to be an excellent benchmark, working far better than some of the alternatives, (coughQuadrantcough).

Smartbench 2011 takes it a step further with multi-core support, as well as a really cool benchmark score aggregator that displays the scores of like-clocked phones and those running the same custom ROM averaged together. Thus, not only does it show you what phones are performing best in the benchmark, but what ROMs and overclocks are dominating the field.

Even if you don't have a dual-core phone, it's a worthy improvement over Smartbench 2010, and a far cry better than the-benchmark-that-shall-not-be-named.

https://market.android.com/search?q=smartbench+2011&c=apps&rdid=com.smartbench.eleven&pli=1

Tegra 2 vs OMAP 4 vs Cortex-A8 vs 2nd-gen Snapdragon

AndroidAndMe has done up a pretty decent comparo of the current Android smartphone kings:

http://androidandme.com/2011/03/news/tegra-2-benchmarks-motorola-atrix-4g-vs-lg-optimus-2x/

Ugh, my blog posts are getting lazy. I've been getting my networking lab put back together though and hopefully I'll be able to start doing some real posts again!

MWC Overload!

I'm just going to drop in here and say that some of the stuff I've been reading from MWC is absolutely insane.

Tegra 3 chips demoed?!

TI OMAP 4430's upclocked SGX 540 outperforming Tegra 2?!

Galaxy S II's Mali-400MP GPU benchmarked!

Qualcomm's successor to Scorpion?!

Cortex-A15 news!

As you can see, AnandTech wins my approval for the best articles. As usual, they provide well-written, well-researched articles that manage to dig up tidbits of SoC information that I'm not able to find anywhere else (and ultimately are accurate!) I'll give AndroidAndMe the runner-up because when it comes to NVIDIA's Tegra platform, Taylor Wimberly keeps his ear to the ground.

I recommend reading through AnandTech's Smartphones section for some great info as to what the SoC future holds in store for us (and the future looks bright!) If you're pondering getting a Tegra 2 phone, trust that AndroidAndMe will keep you up to date on any developments.

I hate to say it boys and girls, but these guys have got everything covered... I've got no inside scoop this time around. That said, I'm glad to see more tech blogs take a much more interested and informed approach to SoC comparison compared to a year ago, and manufacturers are releasing much more information about their chips now that the mobile market is interested in more than just clock speeds.

Thank you, tech bloggers. I originally wrote my Hummingbird vs Snapdragon article out of frustration with the amount of poor information available to those wanting to compare or understand ARM hardware. Since then, perhaps due to the increased availability of information available by the SoC manufacturers, we're seeing much-more informed articles about ARM hardware making it out to the masses.

I may end up on the sidelines, but I'm happy knowing that readers have a lot better reading material to base their smartphone investment upon!

Fun with Tasker Part I: Weather-adaptive alarm clock.

One of those things I always dreamed of having was an alarm clock that woke me up early on those mornings where Mother Nature decided to hand me a nice blizzard before work or school to struggle through.

A couple months back I started playing with Tasker, an amazing Android application that you've probably already heard me gush about in previous posts. In short, for about the price of a Value Meal at McDonalds, Tasker allows you to set up triggers on your phone that you can use to carry out a virtually limitless set of actions. And really, that'll pay for itself, because you can set it up to do countless things for you that other applications charge for. I've got a bunch of profiles I've set up and I'll be sharing them here on my blog over a period of time.

So I'll cut to the chase. I used Tasker to create a weather-adaptive alarm clock, and posted the profile on Tasker's Wiki page, so feel free to try it out!
http://tasker.wikidot.com/weather-clock

More on Samsung; the good, the bad, and the ugly.

Well my last post was the good... now we're about to see some of the bad and ugly. I've been on XDA-developers.com a lot in the last couple months, (I've got over 100 posts there). Today an anonymous tipster posted some insight into why none of the Samsung Galaxy S phones have received Android 2.2 (FroYo) officially yet.

Anyhow, read past the break, I'll let his post speak for itself.

Mystery (probably) solved; how Samsung pulls off its GPU magic.

EDIT - Hmm. One of my readers (who has been an enormous resource in the past) has posted below in the comments why I am likely incorrect in my theory. Be sure to check out the comments at the end of the article!

So, despite my efforts to pull myself away from ARM architecture, Android, and specifically, the mysteries surrounding the Hummingbird processor, I can never really extract myself. One of these days I'll get around to obsessing over something else (hopefully career-related) but until then, I'll let you know what I think I've uncovered as the solution to how Samsung solved the GPU bandwidth issue (which I puzzled over in my original Hummingbird vs. Snapdragon article.)

There have been a few opportunities where I've had to step in and correct people when they post that a Galaxy S phone has only ~320 megs of RAM. It's an error I see made frequently when people use Android system info applications that can only see the 320 megs of volatile memory, despite the fact that the phone does actually contain 512 megs of RAM. We see it happen every time a new Galaxy S phone is leaked, even the Nexus S.

The explanation for this has always been that a certain amount of memory have been "reserved" by Samsung for the Android OS, and that memory is not visible nor available to applications. Despite this, I've never been able to figure out exactly how the system provides the 12.6 GB/sec of memory bandwidth it (theoretically) needs to push out 90 million triangles/sec with the PowerVR SGX540 GPU.

I'm not quite sure how it happened, but in my meanderings across the interwebs, I ran across the following image on odroid.com, of the block diagram of the S5PC110 that they use for their developer board.

Friends don't let friends use Quadrant...

Image courtesy cicada

You've heard my express my concerns over the benchmark tool Quadrant recently.

Well, I decided to put it to the test, and in doing so, I've set some records. Read on past the break!

Insights into the MicroSD card black markets...

Trust me, if China's hardware black market fascinates you like it does me, you'll find this blog post very interesting.

http://www.bunniestudios.com/blog/?p=918

I've never read anything else by this guy, but apparently he's a production manager for the Chumby, which is a rather interesting piece of hardware itself, particularly if you're the kind that likes to tinker.

Essentially, his production line ran into a rash of quality control failures and upon investigation, he found that Kingston had sold him a large batch of MicroSD cards from a very questionable source.

He goes into great detail and even drops a bunch of chips into acid to find out where they actually originated from. I learned a lot reading this article, and will undoubtedly be looking much closer at the SD cards I purchase in the future...

Flaws in Quadrant demonstrate the need for care when analyzing benchmarks

Android benchmark enthusiasts, check out this article: http://briefmobile.com/cyanogen-demonstrates-quadrants-flaws

I'm not sure how I've missed this article, but it's quite interesting. I knew that the problem with the Quadrant I/O performance in the Galaxy S phones (causing them to score significantly below phones like the Droid X, which do not have as powerful a CPU or GPU) could be remedied on the I9000 Galaxy S and the Captivate using a fix from XDA developers.

The above article demonstrates however that the issue may go beyond the way the file system is set up in the Galaxy S. While the fix does produce actual performance gains on the hardware, phones like my Epic 4G apparently have no need for the fix. While Quadrant scores are still affected, Samsung appears to have made changes to the file system on the Epic 4G to allow for quicker loading of data from NAND flash instead of the SD card.

TL;DR - An I/O bug in other Galaxy S phones was rectified in the Epic 4G, but the performance gain is not reflected by Quadrant benchmarks.

How To: Manage an Active Directory directly from a remote PC.

The Active Directory Users and Computers MMC is commonly used to administer users in an Active Directory via the domain controller. The MMC snap-in is designed to be used by a user that exists on the domain that is being administered; it will determine your rights to make changes to accounts based upon your current login ID.

So let's assume you want to manage an Active Directory on a different domain than the one you are on. Not only do you need to log in as a user on that domain, but you also need to force the snap-in to connect to a seperate domain controller. To do this, you will want to create a .BAT file that employs a runas command. (NOTE: This method can also be used as an additional layer of security so that you can administer the Active Directory from a non-administrative account, avoiding the risks of a trojan or virus gaining access to Active Directory information.) Hit the Read link for details!

Poll Closed: Which Galaxy S Phone should I get?

NOTE: I won't be direct linking the polls any longer. It looks like Google reuses their poll IDs, so over time it'll just end up showing the results of someone else's poll anyhow. I will be posting the numeric results however.

Below are the results of the poll:

Verizon Fascinate 3 (13%)
Sprint Epic 4G 11 (50%)
AT&T Captivate 3 (13%)
T-Mobile Vibrant 5 (22%)
Votes so far: 22

FroYo on the Epic, coming Soon™

Report is in that Sprint has released Android 2.2 (FroYo) for the Epic in beta form to select Sprint employees. The FroYo build was leaked to XDA-Developer "noobnl", who has chosen not to leak it partly because the build is incomplete and buggy, and partly to protect the indentity of the Sprint employee who distributed it. He did however distribute the build to two other trusted developers who will use the code to prepare custom FroYo mods.

The FroYo build does not appear to contain USB TV-Out and FM tuner options that many Epic owners have been clamoring for, since it appears it's merely a software / firmware issue to enable these features. We may have to wait for XDA-Developers or Cyanogen to add these features. And, speaking of Cyanogen, it appears that they have been working on Cyanogen 6.1 for the Epic, which could end up being pretty... well... epic.

So, long story short, FroYo is coming to the Epic 4G as promised... so fellow owners, hang in there.

UPDATE, 11/13: It seems XDA-Developers has been working faster than expected. Only 1 day after I posted this, the following rooted leak of Android 2.2 was posted. This build is, for the most part, stable, though some applications will force close (however, this is quickly being rectified on a day-by-day basis). Stock browser performance is somewhat poor and there are a few other minor quirks. Quadrant performance is not stellar, but it is a beta build and we've already discussed why Quadrant scores should be taken with a grain of salt on Galaxy S phones.

I may load it onto my phone later today if I have time.

The Epic Experience

I finally got around to rooting my Epic 4G the other night, and after replacing the stock recovery boot software I proceeded to install the Phoenix kernel and the Epic Experience shell.

I have to say, I'm very impressed with the performance of the kernel and the features provided by the shell. In addition to some nice little tweaks offered by the shell (such as 270 degree rotation, performance tweaks, additional options, removal of ads, and all the software on the other Galaxy S phones), the kernel has managed to run my Epic for over 16 hours from full to empty, including 10 hours of standby, 1 hour of light use, 2 hours streaming Pandora via the speaker at nearly max volume, and about 3 hours of video playback with the screen brightness at max and speaker blaring. All with a boot sequence that takes about half as long and no loss of Android speed or performance.Very cool!