Cambium and Management vlans

Just a quick diagram on how to separate Management traffic on an ePMP network. The aps and CPE are in bridge mode in this setup. The Cambium CPE are in bridge mode with CNPilot routers doing PPPoE, which the ISP has control over as a managed router.

Our netonix has a tagged vlan for the management interface and an untagged vlan for the customer (PPPoE traffic).

The mikrotik router is trunked to the netonix on port 12 to complete this setup.

Internet Freedom transparency rule for xISPs service

The Federal Communications Commission’s Internet Freedom transparency rule, 47 CFR § 8.1, requires an Internet service provider, or ISP, to publicly disclose information about its network management practices, performance characteristics, and commercial terms of its broadband Internet access services.

https://www.fcc.gov/isp-disclosures

MTIN is now offering a full turnkey service for your website to be compliant with the Internet Freedom Transparency rule.  We have two options.  For a document you fill in yourself it is $200.  For a turnkey document, you can export to HTML or link to a PDF from your site it is $300.

Contact us for details 

Thoughts on carrier redundnacy

Recently there have been discussions on some lists about carrier redundancy.  I figured I would sum up some thoughts and add my own,

In today’s world of consolidation, takeovers, and cost saving measures carrier redundancy is something one should pursue with due diligence.  Below are some questions to know about your existing provider and any future providers. If you know this you can compare the differences between two providers.  By knowing the answer to these questions you can add two carriers which will complement each other.

1.Where does my circuit go when it leaves my equipment? Look at this from a regional perspective.  Where does it travel in the city? Where does it travel to the next city?

2.Does the provider’s lines share conduit with other providers?  They might not know this, but if you have two providers you can compare routes.  If they are in the same conduit or in separate conduit in the same trench that might not be ideal.  A backhoe could take both out. Do they share space inside the path with other carriers as well? If so, this could cause issues with contract disputes, not paying bills, and other business-related functions.  Imagine if carrier A is sharing conduit with Carrier B. Carrier A goes out of business and holds the conduit contract.  Where does that leave Carrie rB?

3.Where is the entry point to the facility for the provider’s circuits? If both come into the same part of the building this could be a potential weak point.  Ideally one would enter from the north (or south or whatever) and the other would enter from a different direction.  Also, they would travel up different conduits on different sides of the building.  This way if something like a car crashes through the building may be one of them will be protected.

4.Does the provider farm any of your circuit out to a 3rd party?  This is good to know when problems arise and the finger pointing begins.

 

5.Use tools such as a “Looking Glass” to see if there are differences in routes.  If you have two backbone providers and they have very similar routes to reach the major sites (ie. Google, Yahoo, etc.) then you could open yourself up for problems with latency and packet loss should those paths become congested of fail.  Ideally, you want ProviderA to have different routes than ProviderB.  This way if something outside their network is causing issues it won’t have as big of an impact on your network.   Think of this as a road.  You might have two roads leaving your town, but you don’t want both of those roads taking the same path to get to the outside world.

 

Also look at this from your own equipment perspective. If you terminate all your circuits on a single router you are dependent on that router. Same goes for anything.  If everything comes in over the same ladder racks that are a point of failure.   If all your equipment is in the same room that is a point of failure.

Redundancy can be as diverse as you want to. It boils down to mitigating the risk.  If you know all the risks you can say “Yeah I am willing to bring my cross connects over a single ladder rack because the likely-hood of that rack failing is a risk I will take.”

 

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Bandwidth and the WISP

This was an older article I had on my blog a few years ago.  Much of this applies still.

Bandwidth is a big hurdle most aspiring WISPs face. The reason is if high-speed alternatives were already in place, the need for a WISP would not be as great.  Sure there are business models in which the WISP can compete with other high-speed solutions. However, the bread and butter of a WISP is going into underserved areas.

You have several options for bringing a connection into your area to re-distribute to your customers. I will outline these and then go into further detail

-Leased Lines (Fractional, T-1, T3, etc.)
-Fiber Optic
-Wireless backhaul
-Cable
-DSL

Leased Lines are the most easily accessible across the United States. However, as more and more providers build fiber it is taking over as the preferred method of connectivity.  Fiber is more “future proof” than a T-Carrier circuit such as a T1 or T3.   Most phone companies can provide t1 service to almost anywhere. This is because T1 service uses the existing copper already at 99% of locations. If you have a phone line you can almost always get t1 service.  Once you go beyond T1 things get a little more complicated.  However, T1 has the ability to do bonding if the carrier and telco support it.  You essentially buy multiple T1s and combine them into a single “pipe”.  This requires the provider to support bonding as well as some special configuration on your routers.

Some questions you should ask your provider/telco.

1.Where is my circuit “homed out of”? This means where does the circuit terminate on the facility end.  You do not want this to be too far. If it is too far your reliability will suffer because you have more distance and equipment to go through.  This raises the likelihood of an equipment failure, backhoe digging something up, & utility poles falling.  The longer the distance also means the “loop charge” will most likely increase.   We will get to that in a moment.

2.There are several types of T1s for our purposes.  Some terms to familiarize oneself with are PRI, channelized, transport, and port fee.

3. Ask your provider to spell out what type of t1 this is.  If you are buying the T1 from a backbone provider such as Qwest, Level3, and others they will typically bundle everything into one package. Ask them to break this down if they don’t.  You want to know what the Local loop charge is, what the port fee is, and what the bandwidth costs.  The local loop is typically what the telephone company charges to deliver the circuit from Point A (their equipment) to Point B (you).  If you are going with a 3rd party, and not the local telephone company, the provider typically becomes the central point of contact for the entire circuit.  This can add a level of complexity when issues arise.

The port fee is a charge normally passed on for connecting to the provider’s equipment.  Say you have a 48 port switch sitting in a CO-Location facility.   For each Ethernet cable you plug in from the telephone company they charge a fee either one-time and/or monthly.  This is just the way it is typically.  One of those “Because they can” charges.  The 3rd charge is the cost of the Internet bandwidth.  A T1 can handle 1.5 Megabits of bandwidth so the cost per Megabit is not as big of an issue because you are not buying in bulk.

4.Ask to see the Service Level Agreement (SLA). If you are unfamiliar with the terms have a consultant look this over.

5.Know where your DMARC location is. This is the spot where the provider’s responsibility ends and yours begins.

6.Ask if the provider can verify with the telco how long the next circuit would take to install. You don’t want to go to order a second circuit and find out the local telephone equipment does not have enough capacity.  This has happened to our clients on many occasions.  This can be a quick process or the telco can take months and months to get around to installing the needed equipment.

References:

http://en.wikipedia.org/wiki/Demarcation_point

http://en.wikipedia.org/wiki/T-carrier

Hangers to help with PIM

Are you running Telrad or Baicells? Need a solution to get every bit you can out of the system? Don’t forget your hangers can influence pim .

Traditional hangers and diameter-specific grommet combinations complicate installations, making it difficult to secure cables from wind and vibration, which can cause passive intermodulation (PIM) problems. 

Check out PIM hangers from Tessco.

ALG Antenna test vs Jirous dishes

The following are results from a series of tests of AGLcom’s parabolic dish antennas on an existing link that is 5.7 miles long. The link typically passes 80-90Mbs with a TX capacity of 140 Mbs and radios used are Ubiquiti AF5X operating at 5218 Mhz.  A full PDF with better Readability can be downloaded here..

The tests were taken in stages:

  1. 1)  The normal performance of the link was recorded.
  2. 2)  The 2′ dish at one end, B, was replaced with the AGLcom, C, dish and the link reestablished.The link performance was recorded.
  3. 3)  The 2′ dish at the other end, A, was replaced with the AGLcom, D, dish and the link reestablished. The link performance was recorded.
  4. 4)  The setting on the AF5xs were adjusted to optimize the link performance with data recorded.
  5. 5)  The 2′ dish, B was put back in the link and the performance was recorded.
  6. 6)  The ACLcom C was put back into place.

The tables below do not follow the test order as the third line of data was actually the last test performed.

Antennas:

A-Jirous JRC-29EX MIMO
B-Jirous JRC-29EX MIMO C-AGLcom – PS-6100-30-06-DP D-AGLcom – PS-6100-29-06-DP-UHP

Results:

Table 1 is the signal strength results of the various dishes on the link. The first line, A-B, is the original Jirous to Jirous. A is the first two columns of the link and are the A side and the last two columns are the B side on the link. What is of interest is that exchanging B to C in the second line brought the signal deviation between the channels to only 1db and 0 db as seen in Table 2. The third line was a result of replacing the horn on the A dish and optimizing the setting on the AF5X radios. This changed the signal by around 7db and improved the link capacity, Table 3. Clearly, the A dish had a problem with the original horn.

In the fourth line, D-B, the signal strength improved as well at the signal deviation on the two channels, Table 2 first two columns. This link was not optimized. The fifth line, D-C is both AGLcom dishes which improved the bandwidth, Table 3, and the signal deviations, Table 2. The final line, D-C, was the previous line optimized. The signal strengths moved closer together and the bandwidth improved.

Link Ch0 Ch1 Ch0 Ch1

  1. A-B  -73 -76
  2. A-C  -73 -74

A*-C -64 -66

  1. D-B  -63 -62
  2. D-C  -62 -62

D*-C -60 -60

-70 -74 -71 -71 -65 -66 -59 -59 -58 -58 -61 -61

Signal Strength (* optimized data) Table 1

Table 2 has four data columns, the first two being the measured results and the latter two being the measured difference from theory. The Jirous and AF5X calculators were used for the theory signals. Clearly the signal approached the theoritical limit with the optimization and with the change of dishes. The optimization improved the signal by ~9db for the link that we replaced the horn on the Jirous and by ~2db for the AGLcom link.

Link dSig dSig A-B 3 4 A-C 1 0 A*-C 2 1 D-B -1 0 D-C 0 0 D*-C 0 0

dSig dSig -16.5 -17.4 -17.0 -15.0 -8.0 -9.0 -13.3 -5.3 -7.0 -4.3 -5.0 -6.0

Signal strength variation from theory Table 2

The band width improvement was more obvious, Table 3, from 22 Mbs to 39 Mbs for the RX and 144 Mbs to 141 Mbs TX for the link with the horn replacement. The bandwidth improvement for the optimization of the AGLcom link was from 61Mbs to 66Mbs RX and from 211Mbs to 267Mbs for TX.

The bandwidth improvement from the original, optimized link to the AGLcom link is from 61Mbs RX to 67Mbs and from 210Mbs TX to 267Mbs. There is a clear improvement for the AGLcom link over the Jirous link.

Link BW-RX

  1. A-B  22.5
  2. A-C  39.0

A*-C 60.9

  1. D-B  61.4
  2. D-C  60.6

D*-C 66.6

BW-TX 144.6 141.4 210.0 211.0 215.0 267.6

Table 3

Conclusions:

The data supports a measurable improvement in both signal strength and bandwidth with the use of the AGLcom dishes. However, it is difficult to quantify the improvement. The Jirous dishes were identical whereas the AGLcom dishes were not. One of the jirous dishes was under performing initially but was repaired for the last tests. Additional testing is needed to provide accurate data analysis and performance comparison. The best performance tests would involve identical AGLcom dishes, ideally two links, one each of both types of dishes.