RE: Experiences with Comcast Ethernet

[Dylan Ebner]

This is what we worry about as well. Right now, when the complaints start 
coming in, we can usually trace the problem to a comcast -> level3 -> qwest 
issue. Our big concern is we start seeing over subscription on the nodes (we 
have dealt with this in the past) and our problems start all over again.

Dylan Ebner, Network Engineer
Consulting Radiologists, Ltd.
1221 Nicollet Mall, Minneapolis, MN 55403
ph. 612.573.2236 fax. 612.573.2250
dylan.eb...@crlmed.com
www.consultingradiologists.com

-Original Message-
From: Bret Clark [mailto:bcl...@spectraaccess.com] 
Sent: Tuesday, January 04, 2011 7:40 PM
To: nanog@nanog.org
Subject: Re: Experiences with Comcast Ethernet


> On Tue, Jan 4, 2011 at 1:05 PM, Dylan Ebner  wrote:
>> My company has about 2 dozen Comcast business cable accounts at satellite 
>> offices around the Midwest. We are looking at adding an additional ISP to 
>> the mix and we are thinking of purchasing an Ethernet circuit from Comcast 
>> in an attempt to increase performance on those connections by keeping all 
>> the traffic within Comcast's network.  Comcast, of course, has assured us 
>> this will result in "noticeable" speed increases for those accounts. I am 
>> more weary. Does anyone have any experience with Comcast's ethernet 
>> offerings? How reliable are they? Do Comcast cable connections see a 
>> significant performance improvement?
>>
>> Dylan Ebner, Network Engineer
>>
It will only help if the performance issues  are related to the Comcast 
Internet peering connections, otherwise you'll see no difference if the 
issues are related to congestion occurring on the coax connections from 
the optical nodes that services each coax feed through neighborhoods and 
business. This is simple over-utilization that (at least in our neck of 
the woods) is becoming more and more a problem as Comcast saturates 
there networks with too many connections...there is only so much 
bandwidth a coax line can handle! I suspect your performance issues are 
related to the latter.
Bret

Re: Experiences with Comcast Ethernet

[Christopher Morrow]

On Tue, Jan 4, 2011 at 4:05 PM, Dylan Ebner  wrote:
> My company has about 2 dozen Comcast business cable accounts at satellite 
> offices around the
> Midwest. We are looking at adding an additional ISP to the mix and we are 
> thinking of purchasing an

you are looking at an additional ISP, like multihoming your offices?
or 'you need more pipe in the offices'?

> Ethernet circuit from Comcast in an attempt to increase performance on those 
> connections by keeping
> all
> the traffic within Comcast's network.  Comcast, of course, has assured us 
> this will result in "noticeable"

If you bought an L2 ethernet link from 'office' to 'somewhere' why
would speed be better? The previous question I asked (clarifying
question) aims to help disambiguate this some...

o If you buy a gig link to Comcast's IP network (with IP services from
Comcast) that's one thing (then all, you hope) offices on the same
network are 'faster'. You won't be crossing any of the (potentially)
problematic isp peering links other folk have mentioned.

o If you are buying ethernet transoprt to connect the offices together
in a large vpls/mpls domain you'll probably be better off speed wise
(unless there is drastically higher latency or loss) vs the existing
links you have to comcast's IP network. (note also the VPLS/MPLS
domain doesnt' imply external connectivity, necessarily)

o If you are buying ethernet transport to link the offices to an
external peering/ISP partner/provider then whatever happens on
Comcast's IP network is immaterial (mostly) to this part of your
network.

-Chris

> speed increases for those accounts. I am more weary. Does anyone have any 
> experience with
> Comcast's
> ethernet offerings? How reliable are they? Do Comcast cable connections see a 
> significant
> performance improvement?
>
> Dylan Ebner, Network Engineer
> Consulting Radiologists, Ltd.
> 1221 Nicollet Mall, Minneapolis, MN 55403
> ph. 612.573.2236     fax. 612.573.2250
> dylan.eb...@crlmed.com
> www.consultingradiologists.com
>
>

Re: Experiences with Comcast Ethernet

[Justin M. Streiner]

On Tue, 4 Jan 2011, Brent Jones wrote:


Note, Comcast Ethernet runs on their fiber network, which sometimes
uses aerial lines, I've heard of others having some disconnects when
poles get hit and stuff.


That's not really specific to Comcast.  Aerial fiber runs are very common 
in many places, and have pros and cons, just like underground fiber.


jms

Re: Experiences with Comcast Ethernet

[Bret Clark]

On Tue, Jan 4, 2011 at 1:05 PM, Dylan Ebner  wrote:

My company has about 2 dozen Comcast business cable accounts at satellite offices around 
the Midwest. We are looking at adding an additional ISP to the mix and we are thinking of 
purchasing an Ethernet circuit from Comcast in an attempt to increase performance on 
those connections by keeping all the traffic within Comcast's network.  Comcast, of 
course, has assured us this will result in "noticeable" speed increases for 
those accounts. I am more weary. Does anyone have any experience with Comcast's ethernet 
offerings? How reliable are they? Do Comcast cable connections see a significant 
performance improvement?

Dylan Ebner, Network Engineer

It will only help if the performance issues  are related to the Comcast 
Internet peering connections, otherwise you'll see no difference if the 
issues are related to congestion occurring on the coax connections from 
the optical nodes that services each coax feed through neighborhoods and 
business. This is simple over-utilization that (at least in our neck of 
the woods) is becoming more and more a problem as Comcast saturates 
there networks with too many connections...there is only so much 
bandwidth a coax line can handle! I suspect your performance issues are 
related to the latter.

Bret

Re: Experiences with Comcast Ethernet

[Brent Jones]

On Tue, Jan 4, 2011 at 1:05 PM, Dylan Ebner  wrote:
> My company has about 2 dozen Comcast business cable accounts at satellite 
> offices around the Midwest. We are looking at adding an additional ISP to the 
> mix and we are thinking of purchasing an Ethernet circuit from Comcast in an 
> attempt to increase performance on those connections by keeping all the 
> traffic within Comcast's network.  Comcast, of course, has assured us this 
> will result in "noticeable" speed increases for those accounts. I am more 
> weary. Does anyone have any experience with Comcast's ethernet offerings? How 
> reliable are they? Do Comcast cable connections see a significant performance 
> improvement?
>
> Dylan Ebner, Network Engineer
>

We have a segment on Comcast Ethernet. We use it for other purposes,
just point to point for our needs, but it has been relatively stable.
However, we ordered 1Gbit, and we do use a full 1Gbit, for the first
few months performance was nowhere near 1Gbit until they upgraded some
equipment internally, but speeds have been stable, and reliability
good.

Note, Comcast Ethernet runs on their fiber network, which sometimes
uses aerial lines, I've heard of others having some disconnects when
poles get hit and stuff.

-- 
Brent Jones
br...@servuhome.net

RE: Experiences with Comcast Ethernet

[Dylan Ebner]

That is what we see too. Our connections are used 24/7 and we need lots of 
download speed so the price/performance is great. Except between 9pm and 1am 
when the links are saturated. 

Dylan Ebner, Network Engineer
Consulting Radiologists, Ltd.
1221 Nicollet Mall, Minneapolis, MN 55403
ph. 612.573.2236 fax. 612.573.2250
dylan.eb...@crlmed.com
www.consultingradiologists.com


-Original Message-
From: David Hubbard [mailto:dhubb...@dino.hostasaurus.com] 
Sent: Tuesday, January 04, 2011 3:10 PM
To: North American Network Operators Group
Subject: RE: Experiences with Comcast Ethernet

With the way their peering is these days, that probably
would result in a huge improvement; we have complaints
all over the northeast from comcast users who are getting
poor connectivity to websites we host as a result of the
overloaded Comcast->Level3 links and nothing we can do
about it even though we both share a non-Level3 provider
since Comcast wants the traffic to head out the bad
links.

David

> -Original Message-
> From: Dylan Ebner [mailto:dylan.eb...@crlmed.com] 
> Sent: Tuesday, January 04, 2011 4:05 PM
> To: North American Network Operators Group
> Subject: Experiences with Comcast Ethernet
> 
> My company has about 2 dozen Comcast business cable accounts 
> at satellite offices around the Midwest. We are looking at 
> adding an additional ISP to the mix and we are thinking of 
> purchasing an Ethernet circuit from Comcast in an attempt to 
> increase performance on those connections by keeping all the 
> traffic within Comcast's network.  Comcast, of course, has 
> assured us this will result in "noticeable" speed increases 
> for those accounts. I am more weary. Does anyone have any 
> experience with Comcast's ethernet offerings? How reliable 
> are they? Do Comcast cable connections see a significant 
> performance improvement?
> 
> Dylan Ebner, Network Engineer
> Consulting Radiologists, Ltd.
> 1221 Nicollet Mall, Minneapolis, MN 55403
> ph. 612.573.2236 fax. 612.573.2250
> dylan.eb...@crlmed.com<mailto:dylan.eb...@crlmed.com>
> www.consultingradiologists.com<http://www.consultingradiologists.com>
> 
> 
> 

RE: Experiences with Comcast Ethernet

[David Hubbard]

With the way their peering is these days, that probably
would result in a huge improvement; we have complaints
all over the northeast from comcast users who are getting
poor connectivity to websites we host as a result of the
overloaded Comcast->Level3 links and nothing we can do
about it even though we both share a non-Level3 provider
since Comcast wants the traffic to head out the bad
links.

David

> -Original Message-
> From: Dylan Ebner [mailto:dylan.eb...@crlmed.com] 
> Sent: Tuesday, January 04, 2011 4:05 PM
> To: North American Network Operators Group
> Subject: Experiences with Comcast Ethernet
> 
> My company has about 2 dozen Comcast business cable accounts 
> at satellite offices around the Midwest. We are looking at 
> adding an additional ISP to the mix and we are thinking of 
> purchasing an Ethernet circuit from Comcast in an attempt to 
> increase performance on those connections by keeping all the 
> traffic within Comcast's network.  Comcast, of course, has 
> assured us this will result in "noticeable" speed increases 
> for those accounts. I am more weary. Does anyone have any 
> experience with Comcast's ethernet offerings? How reliable 
> are they? Do Comcast cable connections see a significant 
> performance improvement?
> 
> Dylan Ebner, Network Engineer
> Consulting Radiologists, Ltd.
> 1221 Nicollet Mall, Minneapolis, MN 55403
> ph. 612.573.2236 fax. 612.573.2250
> dylan.eb...@crlmed.com<mailto:dylan.eb...@crlmed.com>
> www.consultingradiologists.com<http://www.consultingradiologists.com>
> 
> 
> 

Experiences with Comcast Ethernet

[Dylan Ebner]

My company has about 2 dozen Comcast business cable accounts at satellite 
offices around the Midwest. We are looking at adding an additional ISP to the 
mix and we are thinking of purchasing an Ethernet circuit from Comcast in an 
attempt to increase performance on those connections by keeping all the traffic 
within Comcast's network.  Comcast, of course, has assured us this will result 
in "noticeable" speed increases for those accounts. I am more weary. Does 
anyone have any experience with Comcast's ethernet offerings? How reliable are 
they? Do Comcast cable connections see a significant performance improvement?

Dylan Ebner, Network Engineer
Consulting Radiologists, Ltd.
1221 Nicollet Mall, Minneapolis, MN 55403
ph. 612.573.2236 fax. 612.573.2250
dylan.eb...@crlmed.com
www.consultingradiologists.com

Re: Experiences with Comcast Ethernet/Transit service

[Bill Blackford]

I've found them to be quite sufficient here in the PDX metro area. They
support all L2 tunnels, in particular, QnQ which I require. We have diverse
paths, multiple strands and multi-colored. We are a bit of a special case as
we are serviced by a group that is intended for government and education
which gives us pricing breaks. The commercial shots I have out to meet-me
POPs are priced diffrently. Their CPE devices are migrating to Cisco ME3400,
etc. devices. Their tiered pricing is based on link speed which I'm not
necessarily pleased with but they're starting to become more flexible. They
aren't currently honoring our P-tags so our locations that may be
oversubscribed have difficulty with priority queueing. Their new core in our
area is a single C 7.6k. I would rather they moved from their older F Big
Iron to a J MX or C GSR, but I'm sure the group that services us is faced
with limited resources (ref pricing breaks earlier). The customer portal
provides custom/customer views on their Orion instance which I find even
more useful than my own Cacti graphs at times. The engineering staff is very
accesible (again our group is unique). I'd like to see them put gear in more
colos and hotels. Their uptime and reliability from my perspective has been
right on target.

-b

On Thu, Jan 7, 2010 at 11:40 PM, Brent Jones  wrote:

> On Wed, Dec 23, 2009 at 1:10 AM, Brandon Galbraith
>  wrote:
> > We're looking at using Comcast's (business) transit and private ethernet
> > services at several client locations and I wanted to see what experiences
> > others have had regarding this. Off-list replies are preferred.
> >
> > Thanks,
> > -brandon
> >
> > --
> > Brandon Galbraith
> > Mobile: 630.400.6992
> >
>
> This was a timely question, as we've have a GigE fiber line with them
> for 6 months now.
> Largely, the link performs at ~999Mbit 99% of the time  :)
> However, we've had two issues with connectivity that seem to originate
> from their network. The link will show up, but both sides of our fiber
> will show 0 frames received, and lots of transmit errors. It takes a
> call into the Comcast NOC each time for them to resolve it, but
> they've been silent on what may actually be going on. These
> interruptions last anywhere from 30 minutes, to the last one almost 7
> hours (luckily over a weekend).
>
> Benefits to this, being Metro Ethernet, they do support tagged VLAN's,
> so cost to entry is low in terms of equipment and setup/support.
>
> Our link goes between downtown Portland, OR, to across the river to
> East Vancouver and Mill Plain.
>
> --
> Brent Jones
> br...@servuhome.net
>
>


-- 
Bill Blackford
Network Engineer

Re: Experiences with Comcast Ethernet/Transit service

[Brent Jones]

On Wed, Dec 23, 2009 at 1:10 AM, Brandon Galbraith
 wrote:
> We're looking at using Comcast's (business) transit and private ethernet
> services at several client locations and I wanted to see what experiences
> others have had regarding this. Off-list replies are preferred.
>
> Thanks,
> -brandon
>
> --
> Brandon Galbraith
> Mobile: 630.400.6992
>

This was a timely question, as we've have a GigE fiber line with them
for 6 months now.
Largely, the link performs at ~999Mbit 99% of the time  :)
However, we've had two issues with connectivity that seem to originate
from their network. The link will show up, but both sides of our fiber
will show 0 frames received, and lots of transmit errors. It takes a
call into the Comcast NOC each time for them to resolve it, but
they've been silent on what may actually be going on. These
interruptions last anywhere from 30 minutes, to the last one almost 7
hours (luckily over a weekend).

Benefits to this, being Metro Ethernet, they do support tagged VLAN's,
so cost to entry is low in terms of equipment and setup/support.

Our link goes between downtown Portland, OR, to across the river to
East Vancouver and Mill Plain.

-- 
Brent Jones
br...@servuhome.net

Re: Experiences with Comcast Ethernet/Transit service

[Jared Mauch]

The Deathstar opt-e-man service says they will knee-cap you at 1Mb/s of 
multicast.

- Jared

On Jan 4, 2010, at 4:56 PM, Holmes,David A wrote:

> PIM-snooping is not in the MEF specs, but should be if multicast is to
> work properly over a carrier's Ethernet service. Regardless of the
> specs, RFPs and other user requirements for Ethernet services should
> include a "must have" clause requiring PIM-snooping functionality. 
> 
> -Original Message-
> From: Antonio Querubin [mailto:t...@lava.net] 
> Sent: Monday, January 04, 2010 12:13 PM
> To: Holmes,David A
> Cc: Brandon Galbraith; nanog@nanog.org
> Subject: RE: Experiences with Comcast Ethernet/Transit service
> 
> On Mon, 4 Jan 2010, Holmes,David A wrote:
> 
>> I do not know of Comcast's Ethernet services specifically, but a
> general 
>> problem with carrier Ethernet services that are based upon the Metro 
>> Ethernet Forum (MEF) is that PIM-snooping is not implemented for 
>> multicast traffic. The absence of PIM-snooping results in the
> carrier's 
>> Ethernet service operating like a 1990's style Ethernet hub in which 
>> (S,G) multicast packets are incorrectly flooded out all user ports.
> 
> Not implemented because it's not in the MEF specs or not implemented 
> because of carrier operational practice?
> 
> Antonio Querubin
> 808-545-5282 x3003
> e-mail/xmpp:  t...@lava.net

RE: Experiences with Comcast Ethernet/Transit service

[Holmes,David A]

PIM-snooping is not in the MEF specs, but should be if multicast is to
work properly over a carrier's Ethernet service. Regardless of the
specs, RFPs and other user requirements for Ethernet services should
include a "must have" clause requiring PIM-snooping functionality. 

-Original Message-
From: Antonio Querubin [mailto:t...@lava.net] 
Sent: Monday, January 04, 2010 12:13 PM
To: Holmes,David A
Cc: Brandon Galbraith; nanog@nanog.org
Subject: RE: Experiences with Comcast Ethernet/Transit service

On Mon, 4 Jan 2010, Holmes,David A wrote:

> I do not know of Comcast's Ethernet services specifically, but a
general 
> problem with carrier Ethernet services that are based upon the Metro 
> Ethernet Forum (MEF) is that PIM-snooping is not implemented for 
> multicast traffic. The absence of PIM-snooping results in the
carrier's 
> Ethernet service operating like a 1990's style Ethernet hub in which 
> (S,G) multicast packets are incorrectly flooded out all user ports.

Not implemented because it's not in the MEF specs or not implemented 
because of carrier operational practice?

Antonio Querubin
808-545-5282 x3003
e-mail/xmpp:  t...@lava.net

RE: Experiences with Comcast Ethernet/Transit service

[Antonio Querubin]

On Mon, 4 Jan 2010, Holmes,David A wrote:

I do not know of Comcast's Ethernet services specifically, but a general 
problem with carrier Ethernet services that are based upon the Metro 
Ethernet Forum (MEF) is that PIM-snooping is not implemented for 
multicast traffic. The absence of PIM-snooping results in the carrier's 
Ethernet service operating like a 1990's style Ethernet hub in which 
(S,G) multicast packets are incorrectly flooded out all user ports.


Not implemented because it's not in the MEF specs or not implemented 
because of carrier operational practice?


Antonio Querubin
808-545-5282 x3003
e-mail/xmpp:  t...@lava.net

Re: Experiences with Comcast Ethernet/Transit service

[Dave Temkin]

I purchased a single GigE transport link from them between a off-net 
building that they lit for us and a lit site.  Install went without 
issue, including pulling in new fiber.  Never underestimate the 
advantages of having pole and conduit rights.  My only complaint would 
be interval - it took nearly 120 days from order to install and much of 
that was seemingly spent idle.


The service itself has been rock solid.  Unfortunately they don't span 
across metros within the same logical network (yet) - this would 
definitely be a bonus.


-Dave

Sean Head wrote:
I just started looking into them as well. Mind of I has for similar 
info? (maybe just keep the responses on list?)


-Sean

On 2009.12.23 01:10:39, Brandon Galbraith wrote:

We're looking at using Comcast's (business) transit and private ethernet
services at several client locations and I wanted to see what 
experiences

others have had regarding this. Off-list replies are preferred.

Thanks,
-brandon

RE: Experiences with Comcast Ethernet/Transit service

[Holmes,David A]

I do not know of Comcast's Ethernet services specifically, but a general 
problem with carrier Ethernet services that are based upon the Metro Ethernet 
Forum (MEF) is that PIM-snooping is not implemented for multicast traffic. The 
absence of PIM-snooping results in the carrier's Ethernet service operating 
like a 1990's style Ethernet hub in which (S,G) multicast packets are 
incorrectly flooded out all user ports. 

If multicast traffic is to be used on the carrier Ethernet service, and there 
is more than one user location, then make sure that the carrier understands the 
implications of the lack of PIM-snooping support.

-Original Message-
From: Brandon Galbraith [mailto:brandon.galbra...@gmail.com] 
Sent: Wednesday, December 23, 2009 1:11 AM
To: nanog@nanog.org
Subject: Experiences with Comcast Ethernet/Transit service

We're looking at using Comcast's (business) transit and private ethernet
services at several client locations and I wanted to see what experiences
others have had regarding this. Off-list replies are preferred.

Thanks,
-brandon

-- 
Brandon Galbraith
Mobile: 630.400.6992

Re: Experiences with Comcast Ethernet/Transit service

[Sean Head]

I just started looking into them as well. Mind of I has for similar 
info? (maybe just keep the responses on list?)


-Sean

On 2009.12.23 01:10:39, Brandon Galbraith wrote:

We're looking at using Comcast's (business) transit and private ethernet
services at several client locations and I wanted to see what experiences
others have had regarding this. Off-list replies are preferred.

Thanks,
-brandon

Experiences with Comcast Ethernet/Transit service

[Brandon Galbraith]

We're looking at using Comcast's (business) transit and private ethernet
services at several client locations and I wanted to see what experiences
others have had regarding this. Off-list replies are preferred.

Thanks,
-brandon

-- 
Brandon Galbraith
Mobile: 630.400.6992