The LiveU Solo does not support different connections using either the same IP address, or an IP address and subnet that would appear to the operating system of the unit as the same subnet.
Detecting IP Conflict
When your modems, or your modems, Wi-Fi and LAN, are setup this way, you may get some or all of these behaviors:
- The unit won't show "Ready" or appear online in the LiveU Solo Portal, even though the modems (dongles) show with green icons in the Connections list on the unit
- Only one, or none, of the connections provide bandwidth while streaming - you may find that only one connection carries all the bandwidth (the unit appears to not be bonding), or that the stream is stuck at 0 Kbps
- When inserting only 1 of 2 modems, that modem works, however when using 2, neither work
- You frequently get the Communication Error message on your unit - particularly only when using it with modems (vs on only LAN or WiFi)
- Only when attaching LAM or Wi-Fi will the unit show "Ready" and appear online in the Solo Portal
Your unit may also show some variations of these issues. The exact behavior can differ slightly based on exact modems, and by random factors like the boot sequence of connections - any combination of these behaviors may be a sign of IP Conflict.
If you have any doubt or unsure, please open a support case and the support team can help identify for sure if the issue is IP conflict.
About Subnets and IP Routing
Once you suspect the issue might be IP overlap or conflict, how can you tell from the IP addresses and subnets assigned to each modem?
The total topic of how IP routing works is outside of the scope of this article, but here are some basics, as having some understanding of the basics will help you with the next step. IP version 4 (IPv4) addresses are made up of 4 sets of digits, each digit is a number between 0 and 255 (an 8-bit number, for those curious! Which is why each number is sometimes called an octet, in IP addressing - its a set of 8 bits). Some of these numbers have special meaning, so not every single number combination can be used as a "normal" IPv4 address. While there are a few other uses, the special meaning we will care the most about is public vs private address space. In theory, your modems and sims could provide an IP conflict in public space as well - but it's far, far less common. 99% of the time when facing IP conflict, its because the modem is using private address space back to the LiveU Solo unit.
Why Some Modems Use Private Address Space
Many years ago, many consumer and industrial modems used specific protocols to communicate with their host operating system - protocols like serial commands (AT commands), QMI, and MBIM. Technically, this type of modem can still use private address space, and in these cases that is controlled by the SIM and network itself. This is still somewhat common for networks such as those from MVNOs.
However, almost all modern (sold in the last 3 years) modems now use another technique to provide bandwidth to a host device - virtual ethernet ports. Why? the answer is pretty straightforward: this makes host OS support much more general, and alleviates the need for specialized drivers on the host OS. Especially for modems sold to consumers, its easy to see why this method of acting like a virtual ethernet port is beneficial to these devices.
The consequence of that is that most of these devices then use DHCP and act like a little router - just like your router at home for your ISP. Meaning, specifically: they provide DHCP to the devices connected to them, that DHCP uses private address space, and whatever address space the SIM uses is obscured by the modem, the host device never knows it.
What a Private Address Space Conflict Looks Like
So now you have a short history of how this became a growing issue and why these devices operate this way. Let's, finally, take a look at the actual math of a conflict, as it makes it easier to spot when you know how it mathematically works.
A very common private address space is:
Many, many home routers start with this space for your home network. It is probably the most common for that situation.
Why the two sets of numbers, divided by a /? The second number is called the subnet mask and it is a bit more complex to understand. But, a sort of convenient shorthand is to think of it this way: a "255" in the same position from the first set of numbers means, only that single numbers is used (in this example above, only "192" is used in the first position, never another number).
But anything less than 255 in that position means more than one number is used, and if its a "0" it means all 256 numbers are used.
So the example above refers to an address space of 256 addresses, starting with 192.168.1.0 and going to 192.168.1.255.
Again, this is just a shorthand and the actual meaning of masks is a mathematical technique, but its a close enough approximation for our purposes here.
Example Conflicting IP Address and Subnets
Her are some example conflicts, with each line in the example below suppose to represent 1 of 2 modems or other connections:
This one is obvious as both are using the exact same address, you don't even have to use the subnet mask. It is clearly a conflcit.
192.168.8.142 / 255.255.255.0
192.168.8.147 / 255.255.255.0
Examples like this are harder to detect, but armed with what you have learned here, you can now see this is also a conflict. While the IP address assignments are 5 digits apart, they are in the same subnet (both are in 192.168.8.x) and the mask ending in .0 means that entire range is the same subnet. So, this is also a conflict and should be corrected, per below.
These are just two examples, if some of the digits in your exact setup differ, it is still a conflict!
So now we are armed with a little understanding of why we might have a conflict and what an IPv4 subnet is and an IPv4 address. Let's look at some actual conflicts.
You Plug In Two Modems That Both Act As Virtual Ethernet Ports
This is the most common example. You plug in two Huawei modems (or Alcatel, or others - just using Huawei as the example), both are the style of modem that acts a virtual ethernet port, both are in their "default" settings.
That means the first modem gives the host device (the LiveU Solo) an IPv4 address via DHCP, likely 192.168.8.100 (the Huawei modems often default to 192.168.8.0/255.255.255.0 as their subnet, and the DHCP range often starts at 100).
The second modem then tries to give the host device the same address. In this case, the DHCP protocol is smart enough to avoid using the exact same IP address, but it does give the second one 192.168.8.101.
Both addresses are a member of the 192.168.8.0/255.255.255.0 subnet, so even thought they are two different addresses, the device (the Solo) can't tell the difference (from an IP address perspective) between the two devices. In effect, it may deliver a packet to the first modem, effectively thinking "this looks like it belongs to you", when in fact it was a packet that needed to go on the second modem - and thus you get all the behaviors outlined in the top of this article.
You Plug The Unit Into the Same Router, Via LAN and WiFi
I think, if you read this far, you probably now see why this is a bad idea. This is a guaranteed conflict as the LAN and WiFi are coming from the same router.
You Plug in One Modem But I Also Join WiFi
Conflicts can happen this way too. What if the WiF I join happens to use the 192.168.8.0/255.255.255.0 subnet? Just as above, we are now in conflict.
Other examples of devices that might use private address space (and very very often use something in the private space of 192.168.x.x) include phones when using USB tethering, MiFis when connecting over LAN, etc.
How To Fix It
This might all start to feel a little overwhelming, with concerns like "How will I never know they are not conflict?" and "if everything favors this 192.168.x.x stuff, won't everything conflict?".
I think the good news here is its actually fairly easy to fix. Almost every device today, with very few exceptions, allows you to change, in its settings, what subnet it uses for its private address space. This wasn't as true years ago, but due to the shift over to the virtual ethernet port style of modems, its much more true today - you can change these settings.
Sometimes, the device may only let you set the "third octet", the "1" in this example:
But that is ok! that i all you need. Sometimes, they would let you change the subnet entirely - but you don't need to, editing that third octet is exactly what we want to do anyway.
And, because you have 256 values to choose from, its pretty easy to choose values that are not likely to conflict with other WiFi, MiFis or your phone. Just avoid relatively low numbers (1 and 8 and 10, for example) and instead use some medium range values (12, 22, 32, whatever you want) and your chances that some other device in the wild has used that same number is very low.
While each device is a little different, here are general steps that are applicable to all devices to help guide you.
Get To The Settings For Your Device
This is step 1 - you will need to access the settings of whatever device you are trying to change: USB modem, MiFi, phone used in tethering, your WiFi router, etc.
For USB Modems specifically, this will mean plugging the modem into a laptop or desktop computer, and following the instructions from the modem manufacturer to get to its user interface and settings. In virtually all cases today, this is done via a web page (served right off a mini web server on the USB modem).
Just as some examples, this knowledgebase has articles on getting to and accessing the interface for a few different modem modems, and its likely that different modems (particularly from the same manufacturer) follow very similar steps:
Find the DHCP Settings
While labeling in the settings section might differ a bit device to device, you know you want to change the subnet used when the device provides DHCP back to the host device, so you are likely looking for DHCP settings, or Subnet settings, look for these labels or labels similar to these.
Once you find them, you may find that all you have to change is the "third octet", the number in the third position of the subnet. In other device cases, you might have to change this number and the IP address of the modem itself (for example, if you change the subnet from 192.168.1.0 to 192.168.12.0, you may find that a second setting change, so that the modem itself no longer acts as 192.168.1.1 and instead acts as 192.168.12.1, is necessary).
If you ever have any doubt about what exact settings to change, once you find them, grab a screen shot and open a support case with LiveU and we will assist you.
Change The Third Number To Something Other Than 1, 8 or 10
Now, change the third number to something other than 1, 8 or 10, and change it something other than what you used for any other device or modem you also changed.
Any number from 11 to 255 will do. Avoiding the "common" ones of 1, 8, and 10 will help avoid future conflicts with WiFi networks or LAN networks.
Save the Settings and Reboot the Device and Solo
Save your settings in the modem, router or MiFis interface, and it will likely need to reboot for those settings to take effect.
Also, reboot your LiveU Solo now with the changed device plugged in, to give the Solo a chance to get a brand new address from DHCP.
Once you understand the basics here, some potential issues will likely seem more obvious to you, and the fix for them will feel more commonplace and quick to implement.
For example: Got two brand new modems that are the same make and model each? they will very likely need to be changed to not conflict.
Plugging one unit into the same network via more than one means (LAN and WIFi)? Always going to be a problem.
Get a new make and model of modem and try it in your laptop or desktop first, and see that it uses a private IP range of 192.168.8.x or 192.168.1.x, or other common ones? Then you are very likely going to want to change it (even if not using two of them), to avoid conflicts with other future networks like WiFi you join.