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WS-12-250-DC 12v input power experience

Posted: Sat Sep 05, 2015 7:09 am
by bmv
This is the first WS-12-250-DC we have fitted to a 12V battery system.
tldr; It's great! :hurray:

The efficiency of the DC-DC transformer in the WS-12-250-DC when working at 12V is not good if you really load up the PoE ports with a load of Watts. You will lose total power, so don't expect 250W. It won't work.
However at this site we are not powering much, so the efficiency is okay and acceptable and we have plenty of capacity left.
When the 12V charger is online, the input voltage is registering 14.7V, and the WS-12-250-DC is only powering a Mikrotik 1100AHx2 (12V), a UBNT Rocket AC (12V) and a Rocket Ti (48V).
This site has 240V AC, however we converted this site to DC as part of a long-runtime UPS system.

So this site is super simple as far as the power side of things is concerned:
- 2 x 70AH 12V batteries in parallel
- 1 x 16A 12V battery charger
- 1 x Netonix WS-12-250-DC

What this site is
This site is a remote POP for us that connects back to our core network via a 13.7mi link where we have a 1 Gb fibre connection to the Internet.
We're getting about 90 Mb real TCP aggregate throughout using a 20 MHz channel which we're happy about.
We have a Mikrotik router at this POP that splits our network up using OSPF, and we have MPLS enabled, plus this router runs a PPPoE server where local clients connect onto before being routed upstream.
The backhaul is a UBNT Rocket AC with a Rocket 34 dish.
There is 1 x UBNT Rocket Ti Sector for connecting to a few clients.
There is 1 x FTTP customers.
There are 2 x fibre connections to remote base stations (no router there, just switches)

Detailed Netonix config
- We have set up a LAG between the switch and the Mikrotik 1100AHx2.
- We are powering the 1100AH from the WS-12-250-DC as ETH13 on this router allows 24V input. Neat.
- Configuring the LAG was based on Chris's post here viewtopic.php?f=30&t=452, where he said that it would split the PAUSE frames to limit the effect that enabling FLOW CONTROL may have. We have the spare ports, we don't need the throughput, but it does add some redundancy perhaps. Overkill perhaps!
- We are also successfully using 2 x TP-LINK TL-SM311LS SFP to connect to some remote TP-LINK MC210CS media converters which are connected to some UBNT Toughswitches (1 will be replaced with another WS-12-250-DC and hopefully we'll have SFP to SFP set up shortly).
- The backhaul connection is a UBNT Rocket AC and we are using the switch as a mid-span PoE injector as you can see with the VLAN config.
- As customers connect via PPP, we have a PPP-Access VLAN and tag this onto the Mikrotik LAG where the PPPOE server is linked to.
- For historic reasons we have had a Sitemonitor at this site to monitor DC voltages and if the power has failed. Read below about what we had before. No surprises perhaps!
- Config is not too difficult. :smile:

Feedback
Installation was a breeze.
This switch is configured exactly like the AC models.
There is no feature loss, and in fact you get some more details on the DC power input voltages and can set the priorities and shutdown/hibernation modes for the various ports in case the power is getting low (if you lose power, or run this off grid and haven't had some sun/wind for a while!)

Before we installed the WS-12-250-DC
So what I didn't mention is what we had before installing the WS-12-250-DC!
We were using a UBNT Toughswitch 5-port hacked onto the DC system. :Cry2:
As it accepts 24V input, and there's a barrel connector onto the back of the UBNT Toughswitch 5-port, this is not a difficult task compared to DC-ing the TS PRO 8-port. However as this site is 12V, we need some 12-24V regulators to ensure stable 24V voltage.
This is a hassle and cost to create.

Also the main problem and reason we upgraded this for a WS-12-250-DC is because of performance problems. BIG performance problems.
Some customers were getting the classic 20 Mb down, 60 Mb up issues.
UBNT really need to stop selling Toughswitches. They really are not good switches.
All the customers connecting off the Rocket Ti Sector were getting horrid latency and packet loss. Really horrid. We thought this was the Rocket radio, so swapped a Rocket M5 for a Rocket Ti and no difference.

BEFORE WS-12-250-DC installed and using UBNT TS-5 (You can see when we were changing things over between 7-8pm):
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before.png (138.9 KiB) Viewed 7365 times


AFTER WS-12-250-DC installed:
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after.png (98.92 KiB) Viewed 7365 times


Config photos
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Re: WS-12-250-DC 12v input power experience

Posted: Sat Sep 05, 2015 8:11 am
by sirhc
Thanks bmv excellent write up with lots of information :thumbsup: