We have one part of our network that rides a T1 provided by others. The current Adtran routers used for that have become impossible to support. I’ve searched for Mikrotik supported T1 interfaces, SFP, external boxes, or any other way to connect Mikrotik routers together over a T1. I see some posts several years old, but nothing current.
I’d appreciate any ideas on how I connect routers with a T1.
Jim
20+ years since I’ve thought about T1 (or HDLC or Frame Relay)…
Adtran used make decent stuff… although I only used to them to get HDLC to Cisco. So “router” sound newer, so IDK…
According to Mikrotik spec page:
https://help.mikrotik.com/docs/spaces/ROS/pages/19136707/Software+Specifications#SoftwareSpecifications-Otherfeatures
T1 and E1 were dropped in 6.x.
They do support HDLC – at least from specs – so if you get your T1 into HDLC you might have a shot. But they don’t say how you’d get HDLC into RouterOS so IDK…
You could research on Sangoma that’s what we used in the old days I don’t know if this works with x86 MikroTik PC never try them 
Meanwhile the “others” who provide the T1 are probably researching how they can keep up that T1 to the single customer that still wants it…
What wrong with your Adtrans? I have a bunch, they seem nearly immortal.
T1 ? I thought T1’s died and went away many many years ago.
- Even the Telcos are moving away from T1’s & DS3’s and moving to fiber when possible.
If you are still using a T1 , consider finding a used Cisco 1720 router with a T1 interface then pass the Ethernet into a ( Mikrotik ) router.
Depending on what you get , you might need an external CSU/DSU.
I believe ROS supported some Sangoma cards waaaaaaaaaaaaaaaaaaaaaaaaaay back in v2.9. In v3, I seem to recall support for all sync serial interface cards was dropped except for the Farsync stuff. Then in v5, those were finally also dropped.
The HDLC mention is only listed under ISDN support. So maybe there is a way to configure it on a virtual network interface (e.g. PPP) hanging off of a standard PC UART-backed RS232 serial port, or something. Pretty sure there is no support in ROS for anything like a UART capable of doing 1.5Mbit/s, which likely makes this a non-starter.
I suppose OP could buy an x86 license and load up ROS 4.17 on an old PC after sniping an eBay auction for a Farsync PCI card. Unless maybe one can make that card work over a PCI-to-PCIe adapter, anything “modern” is probably out. And of course, with something as old as 4.17, be liberal with adding firewall drop rules on the input chain, and turn off as many IP services on ROS as possible…
I’m sure that they would love to decomisson those lines and replace with a Ethernet service instead. No one want’s to keep providing E1/T1 lines to customers.
Go look on Ebay for RAD RICI, Cisco:s with PRI HWIC and so on.
When I was handling T1’s and DS3’s, we had a few Ethernet-over-switched-circuit devices that we sometimes used, allowing us to plug whatever routers (or switches) on each end into the Ethernet ports, and the device would mux the traffic across a number of T1’s (1-4 usually) or a DS3.
I actually have a pair out in my shop acting as rack-mount shelves, but I imagine they still work just fine should you need something.
Thanks for all the responses.
We have worked with the folks that provided the T1 on their microwave and will be moving to a VPWS on that microwave on Weds.
The main issue with the Adtrans was that the PIM-SM functions were enabled on both ends of the T1 to allows multicast (which we need for a multi-point radio system). Two queriers in the network caused problems with radios staying on line. I could not figure out how to disable the querier function without disabling multicast routing entirely.
They are now out of the circuit.
However, now testing in the lab I now see another issue. I enabled PIM-SM on a router central to the network, including a querier. The idea was that when the third radio was connected, or more in the future, the querier would find them and let them join. If find if the network is fully up (and two radios are talking), and I power up the third, it sends a join message then talks to the other two. All good. But, if the radio is on and I then connect the network, it never joins.
Using Torch, I do not see the querier sending messages. I expect those to be to the multicast group address, and be from 0.0.0.0 per the documentation.
So the querier does not seem to be asking if their are devices that want to join the multicast group.
Jim