ISP port blocking practice

> Isn't blocking any port against the idea of Net Neutrality?

Yes.

Owen

No.

The idea of net neutrality, in this context, is for service providers
to avoid making arbitrary decisions about the services that a customer
will be allowed.

Blocking 25, or 137-139, etc., are common steps taken to promote the
security of the network. This is not an arbitrary decision (and I am
defining it this way; I will not play semantics about "arbitrary".
Read along and figure out what I mean.) For 25, SMTP has proven to be
a protocol that has adapted poorly to modern life, and a variety of
issues have conspired that make it undesirable to allow random home
PC's to use 25. Reasonable alternatives exist, such as using 587, or
the ISP's mail server. A customer isn't being disallowed the use of
SMTP to send mail (which WOULD be a problem). A customer may use any
number of other mail servers to send mail. Not a serious issue, and
not arbitrary... it's generally considered a good, or even best
current, practice.

Blocking VoIP from your network to Vonage, because you want your
customers to buy your own VoIP service? That's a very clear problem.
There's no justifiable reason that any viable broadband service
provider would have for blocking VoIP. Yet there could be a reason
to forbid VoIP; I can, for example, imagine some of the rural WISP
setups where the loads caused on the infrastructure interfere with
providing service.

Similarly, it'd be ridiculous to expect an 802.11b based rural WISP
to be able to support HD Netflix streaming, or dialup ISP's to be
able to support fast downloading of movies. These are not arbitrary
restrictions, but rather technological ones. When you buy a 56k
dialup, you should expect you won't get infinite speed. When you
buy WISP access on a shared 802.11b setup, you should expect that
you're sharing that theoretical max 11Mbps with other subs.

It gets murkier when you get into situations such as where your
cableco has sold you a 15Mbps Internet connection, but proceeds to
"traffic engineer" your activities down to a slower speed. There
are real questions that should be addressed; for example, if you
are paying extra for a "premium" service (as in when the default
speed is 7Mbps and you've upgraded), should a customer expect that
they will actually get substantially more capacity? How does the
reliance on overcommit affect things? The ideal is to sell a
high speed connection to someone who uses none of it, of course...
but if you're selling lots of capacity, and betting that only a
little will be used at a time, and you've guessed wrong, the big
question is, is that tolerable, or is net neutrality going to
force you to provide what you've sold?

So, now, back to blocking... many service providers block 80, on
the basis that they don't want customers running servers. This
could very well be a net neutrality issue. It's probably not a
security issue. It's a decision being made at a business level, in
order to promote the purchase of "business class" services. It's
an arbitrary decision about what a customer will be allowed to do.

There's lots of interesting stuff to think about. Net neutrality
isn't going to mean that we kill BCP38 and port 25 filtering. It
is about service providers arbitrarily interfering with the service
that they're providing. Customers should be given, to the maximum
extent reasonably possible, Internet connectivity suitable for
general purpose use. Where service providers start infringing on
that, that's what should be addressed by network neutrality.

... JG

Isn't blocking any port against the idea of Net Neutrality?

Yes.

Owen

No.

The idea of net neutrality, in this context, is for service providers
to avoid making arbitrary decisions about the services that a customer
will be allowed.

Right.

Blocking 25, or 137-139, etc., are common steps taken to promote the
security of the network. This is not an arbitrary decision (and I am
defining it this way; I will not play semantics about "arbitrary".
Read along and figure out what I mean.) For 25, SMTP has proven to be
a protocol that has adapted poorly to modern life, and a variety of
issues have conspired that make it undesirable to allow random home
PC's to use 25. Reasonable alternatives exist, such as using 587, or
the ISP's mail server. A customer isn't being disallowed the use of
SMTP to send mail (which WOULD be a problem). A customer may use any
number of other mail servers to send mail. Not a serious issue, and
not arbitrary... it's generally considered a good, or even best
current, practice.

A common practice of breaking the network for your customers does not
make the network any less broken and does not make the action network
neutral

The SMTP protocol has adapted just fine. Certain operators of SMTP
servers, on the other hand, are a different issue. I don't take exception
if you want to block those SMTP servers. I do take exception if you
block the protocol entirely.

587 is the exact same protocol as 25, just with different host configuration
policies. As such, I would hold up 587 as an example to prove my point.

Blocking VoIP from your network to Vonage, because you want your
customers to buy your own VoIP service? That's a very clear problem.
There's no justifiable reason that any viable broadband service
provider would have for blocking VoIP. Yet there could be a reason
to forbid VoIP; I can, for example, imagine some of the rural WISP
setups where the loads caused on the infrastructure interfere with
providing service.

Some providers block outbound 25 to other email service providers
because they want your outgoing email to go only through their
own unauthenticated, unsecure mail servers. (I have had at least
one former ISP refuse to unblock port 25 or 587 for me to a host
that was running TLS and SMTPAUTH while they insisted that
I use their port 25 server which did not listen on port 587 and
would not accept TLS or SMTPAUTH).

Similarly, it'd be ridiculous to expect an 802.11b based rural WISP
to be able to support HD Netflix streaming, or dialup ISP's to be
able to support fast downloading of movies. These are not arbitrary
restrictions, but rather technological ones. When you buy a 56k
dialup, you should expect you won't get infinite speed. When you
buy WISP access on a shared 802.11b setup, you should expect that
you're sharing that theoretical max 11Mbps with other subs.

Right... Those are not arbitrary, they are valid. Blocking all access
to port 25 is, on the other hand, arbitrary.

There's lots of interesting stuff to think about. Net neutrality
isn't going to mean that we kill BCP38 and port 25 filtering. It
is about service providers arbitrarily interfering with the service
that they're providing. Customers should be given, to the maximum
extent reasonably possible, Internet connectivity suitable for
general purpose use. Where service providers start infringing on
that, that's what should be addressed by network neutrality.

BCP-38 is good. SMTP blocking is not in BCP-38.

Not allowing a user to send forged packets is a perfectly legitimate
action. Not allowing a user to send or receive valid packets
properly formatted, carrying legitimate traffic for purposes which
are not a violation of the providers AUP, on the other hand, is
not good.

Owen