[Icecast-dev] multiple connection (be careful with carrier-grade NAT)

[Christoph Zimmermann]

Hi all

> I didn't pick up the data from the access file, just from the error
> file...

I would have a look at them. My guess is (I explain below why) that you
will see different agents for your multiple connections.

> The situation that I'm describing is very different, 20-30 (and once
> even almost 40) "listeners" from the same IP, for a long time. Each
> "listener" using true bandwidth.
> The IP source is from Vietnam, Korea...i really think that abusing
> its what I'm talking about. 
> ( What a mobile device will handle 30 instances for 20 minutes? )

The short answer is: Carrier-grade NAT
https://en.wikipedia.org/wiki/Carrier-grade_NAT

Longer story:
Back in 2011 the available IPv4 addresses ran out. All of them.
As you know, you need a public IP address to be able to receive Data
from a server. But in the meantime several hundred million mobile
phones got connected to the Internet.

An ugly way to handle this bad situation is to use Carrier-grade NAT,
means that thousands of mobile phones share the same public IP address.
The clean solution would be to use IPv6. Icecast is IPv6 ready.

I'm quite sure that it explains your situation, especially because you
get this connections from Korea and Vietnam. The Asian region has much
fewer IPv4 addresses to use compared to earlier connected
regions (USA, EU), so Carrier-grade NAT is way more common in Asian
mobile networks.

I was searching for a good explanation and a list or so of networks
known to use Carrier-grade NAT. But I didn't found a list. This
presentation is somewhat OK for what I explained:
https://www.apnic.net/__data/assets/pdf_file/0007/53890/8-sp-ipv4-ipv6-coexistence.pdf

> Any idea to handle situation like that one?

Be happy and celebrate that you have so many listeners from this
countries.

All the best,
Christoph