cisco-configuration-for-usbc

Running Into Charging Issues with Your PoE+ to USB-C Converter or Other PoE Devices?

There’s a little known default feature in your Cisco enterprise switch that prevents you from getting the most out of your PoE+ devices, especially when using a PoE+ to USB-C converter for iPad Pro, Surface Go, Samsung Tab, and other devices.

While your Cisco 9400 or 9300 model switches are rated for PoE+ and capable of negotiating PoE+ class 4 devices, they will default to only negotiating 15.4 watts with your PoE converter unless you configure your switch for 2 event classification.
USB-C devices, including the Surface Go and Surface Go 2, require 18 watts or more to charge properly and communicate. You can see why below

In that case, you’ll know the default setting is wrong because:

1 – You’ll see the port only negotiates 15.4 watts of power

2 – Your USB-C device will either not charge properly or will begin to lose battery charge even if it shows it is charging

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Table Of Content

Downtown Amman: Wasat Al-Balad
The Ancient Roman City of Jerash
Amman Accommodation: Kempinski Hotel
Return after a long week of memories

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Configuring Your Enterprise Switch for 2 Event Classification

Fortunately, it’s a quick, well-documented setting you just need to update for the ports you’re planning to use for your PoE+ device. You can find the instructions from Cisco here:

2 EVENT CLASSIFICATION

Or just go to your switch terminal and follow these steps:

Switch> enable

Switch# configure terminal

Switch(config)# interface gigabitethernet2/0/1

You can also configure multiple ports on a switch at one time by choosing a range like

“gigabitethernet2/0/1-24”

Switch(config-if)# power inline port 2-event

Switch(config-if)# end

Why don't we just make their devices LLDP-compatible?

You can read Poetexas's white paper on why PoE LLDP is not compatible with the IEEE 802.3 PoE devices and USB.

Simply put, LLDP and USB are not compatible power standards. They simply work differently.

While we recognize the huge benefits to our customers to not require them to reconfigure their switches, the challenge comes down to what LLDP is and how USB works. LLDP is designed for computers and processors to share vital information with each other at the lowest level possible which works great for an end device like a computer or a phone with a processor on-board and its MAC address, in particular for our case one that can boot and start communicating in a low power mode.

Unfortunately, USB-C devices and the USB protocol doesn’t behave that way. Take a Microsoft Surface Go or an iPad Pro, for example. Their default initial power demands are 18-22 watt PD profiles. If you connect a USB-C hub or dock that offers to provide power to the device without the correct power delivery profiles sufficient to charge the battery, it will reject the device and disable the USB-C port which protects your device from defective or improperly built USB devices. You want that.

On the other hand, it is the end device like the PC or tablet that does LLDP communication with the network once it is connected. So it will not connect to the network through the USB-C port until it has received a correct power profile from the hub. So in this case, the iPad Pro or Surface Go cannot communicate its power requirements back to the network switch until after it has received sufficient power to make the connection.

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And, since you’ll likely point out that the LLDP can happen before you connect the power by disabling the USB-C PD, yes, you can conceivably start with a charged tablet negotiating power then turning on the Power Delivery charging. There are two challenges there as well:

1 – We would need to customize the LLDP drivers on all devices which is considered basically a change to the kernal level programming since this communication works at the lowest levels. Device manufacturers control that very carefully and will be slow to consider that change.

2 – Even if we did achieve that level of change, if the device drains the battery for any number of reasons including power outages or being disconnected for a time, the tablet or PC would be unable to charge, boot up, connect LLDP, and start battery charging without the PD profile. Experience has shown customers cannot guarantee that only charged devices will connect to the network.

So, yes, making switch changes does drive an added layer of configuration, the change provides more reliable and consistent performance in all situations with your USB-C device.

This article was provided by our strategic partner, PoE Texas. View the original here

The Ancient Roman City of Jerash

One of the best things to do in Jordan is to visit the ancient city of Jerash, considered one of the best-preserved Roman-era cities in the world. Actually, Alexander the Great originally founded Jerash (or Gerasa) as a Greek City in the 4th Century BC.

Unlike other ancient Roman cities, you’ll see little restoration; buildings are as it was during the Roman days (or how it has crumbled since). Contemplate that as you walk around exploring what’s left of cultural centers like temples, theaters, and hippodromes. White Australia has such a short, colonized history that you wouldn’t find a building under 200 years old.

You can still see the Greek inscriptions in the crumbling remains of the façade that once faced the city. About three hundred years later, the Romans took control where it grew to be one of the most impressive Roman cities to ever exist.

Amman Accommodation: Kempinski Hotel

To be honest, I wasn’t expecting such a nice hotel to be part of a tour. Kempinski Hotel was in a great location in Amman’s central business district, the service was outstanding, and the rooms were very comfortable with the biggest and best pillows I’ve ever had. The bathroom towels were gigantic and just as luxurious as the fluffy robe. I couldn’t have wished for a more comfortable bed for the 13 hour sleep I had on my first evening - after 30 hours without it.

Spending 15 minutes each day in the complimentary steam and sauna room in the Spa helped me recover from jet lag. The buffet breakfast and dinners were also delicious and full of Jordanian food. Hotel breakfast and dinner buffets are included in the Globus tour. There are local restaurants within walking distance to the hotel if you want to eat out. You will love having 5 Star accommodation at affordable prices on your Escape by Globus tours.