HD1 Dome + SIM injector + Marine Feedback

I’ve installed a number of HD1 domes and SIM injectors in the last 6 months, and I have been iterating over my own boats system pretty much every week. This post is going to cover a number of issues that I’ve found that I think warrant some direct attention if Peplink wants to have a better offering in the marine market.

Some of these issues have been reported in different areas, but I’m trying to focus on one post with a holistic approach to a specific design. This design is for coastal cruising in particular, not offshore. It is also for the moderate to higher end recreational user, not mega yachts.

I have a mix of different Peplink devices that I’ve run through the mix and have posted a number of times before trying to find the right set, and I don’t believe it exists.

The use case is someone who wants at least two CAT18 radios for redundancy combined with SpeedFusion and is not interested in starting their own antenna farm to make this happen. In order to have proper separation, cable lengths and quantities of cables are just not tenable with CAT18.

That and the advent of the HD1/HD2 Dome (and a few other lesser known competitors) showing the marine market that you can have near zero loss and much longer cable runs of CAT5/6 to something indoors. For sailboats in particular, this is a godsend given the limited real-estate near the cockpit, and the tendency to place anything like this on a spreader.

On non-mega yachts, we have lots of other poorly wired things causing lots of interference, and cable chases are very full. Expecting someone to run 4 or 8 cables from a router to two 4x4 MIMO antennas isn’t practical, and in most cases, they will perform poorly.

Another approach has been to recommend some sort of box, fake satellite dome, etc. and put smaller Puma 401 antennas inside of it with the router. This creates a whole host of maintenance and heat issues, and also is a real estate issue on non mega-yachts.

The solution that seems to be pretty close to a fit is the following:

  • 2x HD1 CAT18 Domes
  • 1x SIM injector
  • 1x MAX HD2 or MAX HD4 MBX (several other potentials here too)
  • A bunch of stuff you shouldn’t need to provide

Above is one of my test boards for one of the revisions of this setup:

  • MAX HD4 MBX as the main router, powered by a 12V to 48V buck converter (silver finned thing in upper middle).
  • The SIM injector is in the bottom right, powered by 12V since I can’t use the PoE function with two HD1 domes (more on this below).
  • Two different (for testing purposes) Tycon 12v to 48v PoE injectors are in the middle to the right of the MBX.

The MAX HD4 MBX, HD2 (when it was being tested), and the HD1 Domes are all running v8.1.1 firmware. I tried this all with 8.1.0 but had other issues. The SIM injector is running v1.1.83 but was running 1.1.68 and other earlier versions.

The MAX HD4 MBX is the main router and uses PoE to power 2x AP One Rugged internal APs. This router is up in my flybridge near cabling going to outdoor antennas that include 2x 2x2 Poynting OMNI-402 antennas connected to Cellular 1, and 3x Puma 401 antennas connected to Cellular 2,3,4. I’m also using WiFi as WAN with the MBX to grab remote WiFi signals when in marinas.

WAN1 and WAN2 from the HD4 MBX go to the PoE injectors, and subsequently to the two HD1 Domes mounted up on the highest point on the boat, the arch. This is where the Poynting and Puma antennas are mounted.

The SIM injector is connected to a LAN port. Another LAN port goes to a switch for other devices elsewhere on the boat.


You cannot have both domes plugged into the SIM injector. I tried the steps listed here Using SIM Injector with 2 HD1 Domes - #2 by MartinLangmaid but they only work if you configure everything and never reboot. On reboot, one dome will always fail to see the SIM injector. I could reproduce this at will. This appears to be related to both domes sharing the same subnet. If I changed one dome to use a different network address, they would both come up, but the one with the subnet that wasn’t the same as the HD4 would of course never find the SIM injector.

I tried this both with the HD4 MBX and the HD2 and a few other products, and it didn’t seem to matter. There does not appear to be a way to have multiple PoE powered devices off of a single SIM injector. The simple fix to this mess above would be to have VLANs or some other method of separating the various devices that could be connected. However, that would require the downstream router device support VLANs on the WAN port as well and allow you to create separate profiles for each.

As a result, you have to have each dome plugged into a separate WAN port, which means they need PoE from something else, hence the Tycon devices.

So with that, now we can stick the SIM injector “behind” the MBX on the LAN, turn on the Remote SIM Proxy feature in the support.cgi pages, and then the domes can see the SIM injector and grab a SIM.

By doing this, we get a side benefit in that the MBX can now see it too, so I can use any of my 8 SIMs on any of the 4 built-in radios in the MBX or the two domes.

You still have to setup the SIM profiles on EACH device, which is very tedious with 8 SIMs x 3 devices. It would be great to have the SIM injector somehow advertise these.


Even with this configuration, I see lengthy times for a SIM to be brought up online. Sometimes it can take upwards of 5 minutes. And there are many, many times in the last 6 months where I have had to reboot everything because two devices can’t use a SIM for some unknown reason after having been using it for days, and no amount of rescanning for a SIM card will fix it. Rebooting seems to solve this.

There is clearly some stability issues with the SIM injector and/or the Remote SIM Proxy feature. Thankfully I live aboard the boat, or at times I would have been completely disconnected and needed to go to site to reboot everything.

In a perfect world, what I’d love to see is:

  • An indoor router device that has 2-3 WAN ports all with PoE so they could power the two HD1 domes
  • SIM injector functionality in the indoor router. It could leverage the on board SIM slots (see below)
  • One or two LTE radios in the indoor router that could use the on-board SIMs, or those SIMs could be used SIM-injector style by the domes. The radios in the router can be less than CAT18 as the use case would be using a booster for really bad signal areas instead of the domes.
  • That same router could have WiFi as WAN, or the 3rd WAN port could be used for a MikroTik or otherwise.
  • The MAX HD2 (non-MBX) is a great candidate for this given it’s price and form factor. The MAX HD2 MBX is 2-3x the cost of the original HD2 and would never be affordable by this particular market.

I don’t want a WiFi antenna in a dome (too many antennas in the current form factor and there would most likely be conflicts frequency wise) or a single dome with two CAT18 radios unless somehow the SpeedFusion endpoints could be somehow paired - I don’t want to have one SpeedFusion tunnel at the dome, and then a second overlaid on top of that plus an additional WAN source if I can avoid it.

I really do not like the SIM injector. I love the concept, but the thing seems horribly buggy and has firmware that doesn’t seem to match any other Peplink product. You can’t even get the firmware without a support ticket… The concept is awesome and I don’t want to undermine that.

If we had a decent router that supported the domes plus a good marine mount for the domes, lots of customers I know would jump at the chance to have an outdoor high performing radio or two without crazy cabling or compromises where they put their router, and have a nice indoor router that they could expand on.

Hopefully some of my testing helps someone else, and perhaps this will help shape a dedicated marine router out of Peplink!


An epic, intelligent carefully consider post Steve - thank you very much.

I bet @Sam_Norris and @Travis are already sketching out a product response based on your feedback.


So you have a HD4 MX with four cellular modems? Plus two domes? Six cellular modems?!

I have a similiar use case to you. Ideally I want dual cellular and 3-4 carrier diverse SIMs plus DUAL band simultaneous WiFi as WAN (so I can connect to both 2.4 and 5ghz WiFi networks simultaneously). Heck, some times, I even wish I had three WiFi as WAN, in marinas, I rarely need to rely on cellular when tied up at a dock. Usually there is marina WiFi and something like Xfinitywifi/CableWiFi in-range. Many times, CableWiFi/marina WiFi is advertised on multiple bands. With two WiFi as WAN, I use speedfusion for a pretty solid connection, but wouldn’t mind adding a third WiFi network for some added stablility (as a fix, right now I have a separate speedfusion profile that ties in 2x WiFi as WAN on BR1 MK2 with the cellular for VoIP, wifi calling, wifi texting, video chats, etc). I would want to be able to select each WAN source independently to “pick and choose” WAN sources across multiple Speedfusion profiles.

1x14 marine mounts are ideal for any antennas and domes. I much prefer not having a “christmas tree” of antennas visible.

I wish there was a dual cellular dual wifi wan dome option but perhaps I could settle for a single modem single wifi option (but not ideal). I much rather run cat 6 cable than LMR-400. Either way, each WAN, regardless of cellular or WiFi, should appear as a separate WAN connection, for Speedfusion profile purposes, management, etc.

I keep my WiFi as WAN separate for LAN WiFi. I think that is important, due to antenna location, fiberglass, bandwidth, etc.

Some questions for you:

  • You mentioned that you you have your setup up on the fly bridge. Is it in a weather tight enclosure? I would be highly concerned in salt environments having any networking equipment that is not protected.
  • Why did you opt for the HD2/HD4 MBX as the “brain”? I am curious why you wouldn’t go for a less expensive Peplink router with no built-in cellular/WiFi (rely on the Domes for that) and figure out WiFi as WAN (perhaps even a Mikrotik or similiar)?
  • Are you concerned about antenna arrangements inside the Domes? I use the poyntings right now with my MK2. My understanding is the dome antenna performance may be limited in “rolling” Sea conditions whereas something like a Poynting would continue to work.
  • Regarding your comment “I don’t want a WiFi antenna in a dome (too many antennas in the current form factor and there would most likely be conflicts frequency wise) or a single dome with two CAT18 radios unless somehow the SpeedFusion endpoints could be somehow paired - I don’t want to have one SpeedFusion tunnel at the dome, and then a second overlaid on top of that plus an additional WAN source if I can avoid it.” >>> can you please clarify how you have it now? Ideally, each WAN (whether cellular or wifi) shows up as individual WANs on a router, and there is only speedfusion set on the one “brain” router…

My biggest concern is price. My Mk2 setup was probably around $1k in hardware (MK2, antennas, indoor LAN AP, cabling, etc). How much was your setup? I could possibly stomach $2k but going to $5-6k will not be tolerable for most Cruisers who want a $1k hardware price point.

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PS. have you had any issues with xfinitywifi as of late? I used to use Cablewifi (Optimum/Altice-based account) and started having issues on my MK2 connecting WiFi WAN in mid-October. I get an IP but the healtcheck fails (MK2 cannot ping yahoo.com - seems no internet traffic will pass to the Peplink device). Previously my WiFi wan setup worked without issue for years, and boom, overnight, it all stopped working (I didnt touch anything). I can connect to an unstable Marina WiFi without issue except the connection is unstable (Cablewifi was more stable - I connected to two different physical ones, one 2.4 and one 5ghz).

The thing that drives me most crazy is having to reboot the Sim Injector to get my HD2 Dome to find the SIM cards again. It normally only loses one sim at a time, thus meaning it is certainly a software bug that needs fixing.

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@joe.richardson, I suggest submitting a ticket for us to take a look.


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Is there any progress on a 1 box solution for running 2 Cat 18 domes with POE, remote sims and speed fusion?


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with dual band simultaneous WiFi WAN would be awesome too…

I am interested in an update on this as well. I have at least 5 potential boating customers a week ask about the HD1 dome but I steer them away from it due to the management required for a system that supports SpeedFusion. This would include 2x HD1 domes, some sort of Balance or MAX router, three interfaces, etc. etc.

Boaters really hate running long cables to antennas, as do I from the install and signal loss perspective. The HD1 dome is a great alternative and it would be awesome to see a central router or device that could do the SIM injection and management of the dome device.