Subject: (usr-tc) Bridged or routed connections?

From: Mark Thornton <[email-masked]>
Date: Wed, 25 Apr 2001 19:24:09 +0000

I have run into a problem in my network that appears to be caused by my DSL
router having the connections appear as bridged instead of routed. It is
causing a throughput bottleneck of 50 to 70%. This is causing me to analyze
my entire network configuration.

Do the connections to a TCH on the HiperArc appear as routed connections, or
as bridged connections?

Mark Thornton
San Marcos Internet, Inc.
512-393-5300

-
 To unsubscribe to usr-tc, send an email to "[email-masked]"
 with "unsubscribe usr-tc" in the body of the message.
 For information on digests or retrieving files and old messages send
 "help" to the same address.  Do not use quotes in your message.

---

From: Marshall Morgan <[email-masked]>
Date: Thu, 26 Apr 2001 03:31:07 +0000

Mark,

Could you please provide more details so we may better understand your
issues.

Marshall Morgan

Internet Doorway, Inc (aka NETDOOR)
http://www.netdoor.com

601.969.1434 x28 | 800.952.1570 x28 | 601.969.3629 x28 | Fax 601.969.3838
----- Original Message -----
From: "Mark Thornton" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, April 25, 2001 12:16 PM
Subject: (usr-tc) Bridged or routed connections?

-

---

From: Mark Thornton <[email-masked]>
Date: Thu, 26 Apr 2001 06:23:25 +0000

Here goes...

We have a core router (3640) and a DSL aggregation router (7206) on either
side of a Emerging Technologies Bandwidth Manager that bridges multiple
ethernet segments. The problem is if there is any address on the ethernet
network that is outside of the primary ip subnet assigned to the network
then the bandwidth manager introduces a 70% reduction in throughput. I could
remove the manager but it is critical to managing the DSL bandwidth. Cisco
originally told us the ATM circuits terminated on the 7206 were routed
connections. In fact they appear as bridged connections to the ethernet lan.
When I assign an ip address from a dedicated subnet for the DSL customers
that is not part of the lan subnet we have significant problems with
throughput and latency. If we assign ip addresses from the lan subnet it
works great. We can route to ip subnets outside the lan subnet if we use a
local ip on the bridge side. This is causing us to reconfigure our network
to accomodate this behaviour.

In the reconfiguration we need to determine how the modem connections are
handled. I know there is some provision for proxy arp in the system as well
routing. I want to assure that my system is configured for routing and does
not appear as having bridged connections. Latency issues are always a
concern for ISP's.

Mark Thornton

----- Original Message -----
From: "Marshall Morgan" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, April 25, 2001 8:28 PM
Subject: Re: (usr-tc) Bridged or routed connections?

> > Do the connections to a TCH on the HiperArc appear as routed
connections,
> or

-

---

From: Marshall Morgan <[email-masked]>
Date: Thu, 26 Apr 2001 08:52:47 +0000

Mark,

First off, you mention how important latency issues are at the end of your
discussion but at the top you mention how it's "critical to managing the DSL
bandwidth" - seems like a contradiction in philosophy at the very least.

On to the problem ...

By using Ethernet Bridging (RFC 2684 / formerly 1483 / Bridged Ethernet
encapsulation from Efficient's webpage) your customers are getting a bridge
connection from their CPE gear to your's (in this case a 7206).  From there
it's a routed connection (as long as the network you are giving them
terminates on the 7206).  Why not use PPPoE to better manage your customers
(radius settings, accounting and such).  We use Bellsouth to provide ADSL
services and have both PPPoE and bridged customers and don't have a problem
terminating either on a 7206.   In addition, why reconfig the network?  Just
make a VLAN for the ADSL service or something similar.

If you want me to take a look at your config I will be happy to see how we
differ in deploying this "losing battle" service (I will be out of town
until Monday starting tomorrow).

Marshall Morgan

----- Original Message -----
From: "Mark Thornton" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, April 25, 2001 11:19 PM
Subject: Re: (usr-tc) Bridged or routed connections?

> > > I have run into a problem in my network that appears to be caused by
my
> > DSL

-