Podcast: Cameron Kilton from Alpha and I talk about LTE

Cameron Kilton from Alpha Wireless and i sit down at the 2019 Indiana ISP meeting and talk about LTE and Wireless operators.  Pardon the rough beginning. the room we were in had a flickering light that took me by surprise near the beginning and messed with my rhythm.

Cameron’s Twitter
https://twitter.com/cameronkilton

Alpha Wireless
https://alphawireless.com/

Ubiquiti releases EdgeMAX EdgeSwitch software 1.8.2

From their announcement

A new software release for EdgeSwitch (all current models) is available here:

EdgeSwitch 1G switch models: ES-48-750W, ES-48-500W, ES-24-500W, ES-24-250W, ES-48-Lite, ES-24-Lite, ES-16-150W, ES-12F,ES-8-150W, EP-S16.

Normal version:
https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-eswh.v1.8.2.5192445.stk
(SHA1: b1f66416276ef7de9abd5d2c50fa79b75d1bfe49) (GPL archive)

LITE version:
https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-eswh.v1.8.2-lite.5192445.stk

(SHA1: 47c11f3ce06d77e450a480877e06d2e72a6c6192)

Mib files:

https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-eswh.v1.8.2.5192445-mibs.tar.gz

(SHA1: 85b3acb15923b94f25bc965a98f72d24a4dac1f1)

EdgeSwitch 10G switch model: ES-16-XG
Normal version:

https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-esgh.v1.8.2.5192445.stk
(SHA1: 4aa6412e4736e9a1314700af3c7d05c61500d20b) (GPL archive)

LITE version:

https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-esgh.v1.8.2-lite.5192445.stk
(SHA1: 0e627ec330e3ec38feca97a2564be701f40ae246)

Mib files:

https://dl.ubnt.com/firmwares/edgemax/EdgeSwitch/v1.8.2/ES-esgh.v1.8.2.5192445-mibs.tar.gz

(SHA1: cb726e10689de0004d08ccc6d26beeec5a9f3f60)

Bug fixes and enhancements

  • [VLAN] reduce maximum VLAN number from 4093 to 256 (Only in Lite version).
  • [SECURITY] fix some issues in the Legacy UI.
  • [SECURITY] fix injection issue in CLI command.
  • [SYSTEM][ESWH] improve system stability.
  • [SYSTEM][ESWH] improve compatibility with SFP+ module (UF-SM-10G-S).
  • [SYSTEM] fix bugs with some specific cases in config checker.
  • [SYSTEM] fix time range multi entries issue.
  • [SYSTEM] add CLI command ‘show mbuf detail’.
  • [SYSTEM] add check for memory tuning.
  • [SYSTEM] reduce the memory usage in firmware upgrade.
  • [DHCP_RELAY] check invalid VLAN value.
  • [DNS] synchronize the static ip-host in system.
  • [CLI][Legacy UI] update copyright for 2019.

Soundproofing your server room

Recently I was asked techniques for soundproofing a server room to keep the noise down in a small to medium-sized office.  Before the discussion dives into the article, there are a few things to keep in mind

1. Don’t let the soundproofing aspect overtake the airflow aspect.  Airflow is critical.
2. Make sure your solution meets fire and building codes.
3. Mass always wins when it comes to soundproofing.

Now on to some ideas.
Acoustic Foam
https://www.thefoamfactory.com/acousticfoam/acousticfoam.html

Ceiling Tiles
Ceiling tiles are typically sound absorbent, but you can get some with higher absorption than others.

Soundproofing on the cabinet
For those of you familiar with high-end car stereos know products like Dynamat and other sound deading materials. The work in two ways.  The first is by adding mass to what the are applied to. Secondly, they are made of materials specially designed to absorb sound. There are many kinds of these on the market. One such product is here on Amazon

Other techniques
Keeping the air conditioner on a decent setting can cause the fans in the equipment not to work as hard. If the device is getting cooled the fans may not have to spin at higher RPMs to move air.  Proper airflow through your cabinets and racks helps greatly with this.  If you have your equipment taking cold air in from the front, where maybe a vent is in front of the cabinet door, this can greatly help.

Supplementing your cooling with a slow moving large fan.  Large fans spinning at low RPMs can move just as much air as smaller fans spinning at higher RPMs.  If your server room needs help this could be an option.

Proper cable management is also essential for airflow.  The better the air moves through the equipment the cooler the equipment will be.  As stated above, cooler equipment means fans are not spinning at high RPMs generating noise.

ePMP 3000: How to test MU-MIMO

http://community.cambiumnetworks.com/t5/ePMP-3000-MU-MIMO/ePMP-3000-How-to-test-MU-MIMO/m-p/102882

Intial MU-MIMO testing after deployment can be performed through the built-in Wireless Link Test Tool.On Wirless link Test page new option has been added for ePMP3000 – Mode. Wireless Link Test can be started to Single SM or to Dual SMs simultaneously.

ePMP eDetect

One of the biggest tasks on a wireless AP is finding clean channels.  Once you find those clean channels, making sure you stay on a clean channel is the next task. ePMP has a feature under tools called eDetect. One of the things this can do is give you an idea of how many devices are on a given frequency.

The ePMP AP you see above is on a 20mhz channel, which is why many home routers and other devices are showing up.  If this was on a cleaner frequency it would look like the following.

While eDetect is not a replacement for spectrum analysis, it can give you a pretty good idea of what’s using a particular frequency.  Please note, you see the most things on 20MHZ channels because that is what most home routers are set to. If you would like to read up on eDetect in more detail go here: https://community.cambiumnetworks.com/t5/ePMP-Configuration-Management/ePMP-Tools-eDetect-Explained/td-p/42997

The addition of RF elements horns to a PTP550 link

Originally posted at:
http://www.mtin.net/blog/the-addition-of-rf-elements-horns-to-a-ptp550-link/

In a previous series of articles we talked about a new Cambium 550 link and the noise challenges we had.  You can start your reading in Part one and Part two.

Due to the frequency challenges, we decided to upgrade the dishes to RF Elements Ultra Horns.

If you recall our spectrum looked like this before.

After the horns. While not a night and day difference you will notice several improvements across the band.  Less red and yellow on the scan and sharper drop-offs. We saw the most improvement in the 5160 area and the 5720 ranges.  And this is with the horns pointed right at the source of most of the 5GHZ noise.   Not much you can do if you are pointed right at the noise.

What did this mean for the link? It meant we were able to find a 200 meg increase because we were able to obtain better modulation on the link.

So while we were not able to filter out all of the noise we wanted, we were able to increase our MCS rates on a very noisy link to increase bandwidth and increase the reliability of the link.  Before the horns, the MCS rates would be in a constant state of flux dealing with noise.

PTp550 Throughput with RF elements horns

Distance:5.03 Miles
Downlink RSSI: -59
ChannelWidth: 40MHZ
DownlinkSNR:33bB
Antennas: RF elements Ultra Horns
Downlink Ratio set to 75/25

Question: Why are you not using channel bonding? 
A)Having some reliability issues with channel bonding at the moment on the 550 platform.

Question: What was the link like before the horns?
Check out this previous post. (pictures are screwed up for now): http://www.mtin.net/blog/the-addition-of-rf-elements-horns-to-a-ptp550-link/

 

 

The Changing RF landscape for WISPs

Recently, there have been some discussions on Facebook about waining support for 2.4GHZ .  KP Performance recently published a Future of 5GHZ and beyond blog post. So why all this focus on 5GHZ and why are people forgetting about 2.4?

To answer this question, we need to update our thinking on the trends in networks, not just wireless networks.  Customers are demanding more and more speed. Network backbones and delivery nodes have to be updated to keep up with this demand. For anything but 802.11 wifi,2.4GHZ can’t keep up with the bandwidth needs.

One of the significant limitations of many 2.4 radios is they use frequency-hopping spread spectrum (FHSS) and/or direct-sequence spread spectrum (DSSS) modulation. Due to 2.4GHZ being older, the chipsets have evolved around these modulation methods because of age.  When you compare 2.4GHZ to 5GHZ radios running OFDM, you start to see a significant difference.  In a nutshell, OFDM allows for higher throughput. If you want to read all about the differences in the protocols here ya go: http://www.answers.com/Q/Difference_between_ofdm_dsss_fhss

Secondly, is the amount of spectrum available.  More spectrum means more channels to use, which translates into a high chance of mitigating interference. This interference can be self-induced or from external sources. To use an analogy, the more rooms a building has, the more simultaneous conversations can happen without noise in 2.4GHZ we only have 3 non-overlapping channels at 20mhz. Remember the part about more and more customers wanting more bandwidth? In the wireless world, one of the ways to increase capacity on your APs is to increase the channel width. Once you increase 2.4 to 30 or 40 MHz, you do not have much room to deal with noise because your available channels have shrunk.

One of the biggest arguments in support of using 2.4GHZ for a WISP environment is the physics.  Lower frequencies penetrate trees and foliage better. As with anything, there is a tradeoff.  As the signal is absorbed, so is the available “air time” for transmission of data.  As the signal travels through stuff, the radios on both sides have to reduce their modulation rates to deal with the loss of signal.  Lower modulation rates mean lower throughput for customers.  This might be fine for customers who have no other choice.  This thinking is not a long term play.

With LTE especially, traditional thinking is being uprooted.  Multiple streams to the customer as well as various paths for the signal due to antenna stacking are allowing radios to penetrate this same foliage just as well as a 2.4 signal, but delivering more bandwidth. These systems are becoming more and more carrier class.  As the internet evolves and becomes more and more critical, ISPs are having to step up their services.  The FCC  says the definition of broadband is at least 25 meg download. A 2.4 radio just can’t keep up in a WISP environment.  I am seeing 10 meg becoming the minimum customers want. Can you get by with smaller packages? Yes, but how long can you maintain that as the customer demand grows?

So what is the answer? Cell sizes are shrinking.  This is helping 2.4 hold on.  The less expensive radios can be deployed to less dense areas and still provide decent speeds to customers.  This same trend allows 5GHZ cells to be deployed as well. With less things to go through, 5GHZ can perform in modern networks at higher modulation rates.  Antenna manufacturers are also spending R&D to get the most out of their 5GHZ antennas. More money in the pipeline means stronger products. My clients are typically deploying 3.65 and 5GHZ on their towers.  LTE is changing RF WISP design and taking the place of 2.4 and 900.

Where does Trill and VXLAN fit in your strategy?

As networking trends yo-yo between layer-3 and layer-2,  different protocols have emerged to address issues with large layer-2 networks. Protocols such as Transparent Interconnection of Lots of Links (TRILL), Shortest Path Bridging (SPB), and Virtual Extensible LAN (VXLAN) have emerged to address the need for scalability at Layer2.   Cloud scalability, spanning tree bridging issues, and big broadcast networks start to become a problem in a large data center or cloud environment.

To figure out if things like TRILL is a solution for you, you must understand the problem that is being addressed by TRILL. The same goes for the rest of the mentioned protocols. When it boils down to it the reason for looking at such protocols is you want high switching capacity, low latency, and redundancy.  The current de facto standard of Spanning Tree Protocol (STP) simply is unable to meet the needs of modern layer2 networks.  TRILL addresses the problem of STP’s ability to only allow one network path between switches or ports.  STP prevents loops by managing active layer -2 paths.   TRILL applies Intermediate System-to-Intermediate System protocol (IS-IS), which is a layer3 routing protocol translated to Layer 2 devices.

For those who say TRILL is not the answer things like SPB also known as 802.1aq, and VXLAN are the alternatives. A presentation at NANOG 50 in 2010 addressed some of the SPB vs TRILL debate. This presentation goes into great detail on the differences between the two.

The problem, which is one most folks overlook, is that you can only make a layer 2 network so flat.  The trend for a while, especially in data centers, is to flatten out the network. Is TRILL better? Is SPB better? The problem isn’t what is the better solution to use.  What needs to be addressed is the design philosophy behind why you need to use such things.   Having large Layer2 networks is generally a bad idea. Scaling issues can almost always be solved by Layer-3.

So, and this is where the philosophy starts, is TRILL, SPB, or even VXLAN for you? Yes, but with a very big asterisk. TRILL is one of those stop-gap measures or one of those targeted things to use in specific instances. TRILL reduces complexity and makes layer-2 more robust when compared to MLAG. Where would you use such things? One common decision of whether to use TRILL or not comes in a virtualized environment such as VSPHERE.

Many vendors such as Juniper, have developed their own solutions to such things.  Juniper and their Virtual Chassis solution do away with spanning tree issues, which is what TRILL addresses.   Cisco has FabricPath, which is Cisco’s proprietary TRILL-based solution. Keep in mind, this is still TRILL.   If you want to learn some more about Fabric Path this article by Joel Knight gets to the heart of Fabric path.

Many networks see VXLAN as their upgrade path.  VXLAN allows layer 2 to be stretched across layer 3 boundaries. If you are a “Microsoft person” you probably hear an awful lot about Network Virtualization using Generic Routing Encapsulation (NVGRE) which can encapsulate a layer two frame into IP.

The last thing to consider in this entire debate is how does Software Defined Networking (SDN) play into this. Many folks think controllers will make ECMP and MLAG easy to create and maintain. If centralized controllers have a complete view of the network there is no longer a need to run protocols such as TRILL.   The individual switch no longer makes the decision, the controller does.

Should you use Trill, VXLAN, or any of the others mentioned? If you have a large Layer-2 virtualized environment it might be something to consider.  Are you an ISP, there is a very small case for running TRILL in anything other than your data center. Things such as Carrier Ethernet and MPLS are the way to go.