This post is a long time coming, but I couldn’t keep it inside anymore. 3G and more recently 4G has taken off in a way that has changed the way we communicate. For Handhelds, Tablets and Laptops instant access to the Internet has never been easier. This is a good thing right? Yes, I do not argue that at all.
The challenge I am going to describe is the same challenge Network professionals have had with all new technologies.
Back in about 1995 we would use 56K Leased Lines to connect two offices together. We started to migrate to ISDN (http://en.wikipedia.org/wiki/Integrated_Services_Digital_Network) dial up. ISDN BRI offered two Channels each at 64K, giving the customer 128K of throughput. Laughable today, but at the time 128K was awesome.
First there was confusion around the Hardware required to terminate the ISDN. A Terminal Adapter (TA) was required, but there was also an NT1 device that was always required but sometimes built into the TA. Although at the time the information about ISDN and how it worked was not easily available (no Wikipedia back then), we were able to fumble out way through enough to figure out the Hardware part of it.
In the beginning we used a Motorola UTA220 and the configuration of this unit was done with a front panel LCD display with three buttons – Yes, No and Home. There were many parameters that needed to be set up, some obvious others not so much. If you missed the menu item you were looking for you would have to go back and start over again. Doesn’t sound to bad…The critical parameters of ISDN were the SPID Numbers and the DN’s. Without these in the configuration the line would not come up.
Each carrier required different parameters in their SPID and DN’s. This is where the real confusion started. I am sure the engineer that set it up and designed the system for (in this case) Bell Canada, knew what was required to set it up, but we could not find anyone to help us. All of the documentation we read told us to use the B channel phone numbers for the SPID and DN’s, but we could not get it to work.
Eventually, somehow and I can’t remember how we figured out that Bell Canada required 00 at the end of the phone numbers for the SPID settings and the DN’s required the Area Code as well as the number. How many days went by before we got this info I have no idea……So we got the TA connected and the channels up… Lets make an ISDN call to another TA and create a line….. No such luck. Every time we tried we got a fast busy. Again, I cant tell you how much effort of days went by before someone (Not Bell Canada) decided to dial a 9 before the number and presto we were in business.
Here we are back in 2012 and we have customers and a lot of them wanting to use 3G/4G as a primary in locations were there are no other options and as a backup to their broadband connection. Rogers, Bell Telus, Shaw and I am sure every other Canadian and US carrier is offering 3G/4G, so they are certainly easy to order. But what are you getting?
From the Carrier side you may get any one of the following:
1. A connection with a private IP address that gets NAT’d to the internet.
2. A connection with a public IP address that gets NAT’d to the internet
3. A connection with a private IP Address that uses a Proxy Server to get to the Internet
4. A connection with a public IP Address that uses a Proxy Server to get to the Internet
A connection with an IP that may be public or may be private that may or may not get NAT’d and/or may or May not go thorugh a proxy server because none of their Engineers, Sales and Operations folks actually know how their 3G/4G network has been designed and deployed.
Then you have the SIM Card / Modem debacle. As you know the SIM card is required from the Carrier to access the Network. In most cases this SIM card gets installed in a 3G/4G modem in the form of a USB stick. Many of the WAN devices now come with a USB slot for just this purpose. Each Hardware Vendor then releases a list of supported USB or Express Card Modems supported. The issue is that these modems are getting changed all the time and the Vendors and Carriers do not seem to be in synch at all.
We have also noticed Regional differences… A card that worked in Ontario with Rogers would not work in Alberta and when we got one working it was Proxying in one place and NATing in the other. WHY? no one knows!
I think there are different sizes of SIM Cards now, which confuses the issue just that much more.
Here is an example of the ongoing confusion from just one Vendor:
Try and find any of this information on the Carriers web site… Non existent! Is it because they want you to lock into three years and use there modem? I don’t know.
Then there are the rates and policies and fine print. Some of the services will detect multiple devices and block access. Some carriers will block IPSec traffic. Some will not provide warnings once you have reached your usage and then charge you exorbitant rates for your overage.
I know that as this technology matures it will get clearer and clearer until eventually anyone can get it working, but as I said earlier until then, it is and will continue to be a challenge.