From: Jay Hanke (Jay.Hanke@midwestwireless.com)
Date: Mon Nov 27 2006 - 11:46:14 ART
When you say "front of the queue" do you mean the LLQ or the tx-ring? My
understanding is that the tx-ring is FIFO and packets are always added
at the back of the line, is this not the case?
________________________________
From: Brian McGahan [mailto:bmcgahan@internetworkexpert.com]
Sent: Friday, November 24, 2006 9:07 PM
To: Jay Hanke; ccielab@groupstudy.com
Subject: RE: LLQ and bandwidth on ethernet interface
Hi Jay,
The LLQ or "priority" statment in the MQC is in effect 100% of the
time. This is due to the fact that even if the output queue is not full
priority packets can experience delay while waiting for large packets to
be admitted to the transmit ring. To prevent this the LLQ send all
packets that "match" to the front of the queue, preempting any
non-priority packets on their path to the transmit ring. Also
congestion is a function of the size of the output queue of the
interface and is not directly related to the provisioned rate or access
rate of an interface.
HTH,
Brian McGahan, CCIE #8593 (R&S/SP)
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
<https://webmail.123together.com/exchweb/bin/redir.asp?URL=http://www.In
ternetworkExpert.com>
Toll Free: 877-224-8987 x 705
Outside US: 775-826-4344 x 705
24/7 Support: http://forum.internetworkexpert.com
<https://webmail.123together.com/exchweb/bin/redir.asp?URL=http://forum.
internetworkexpert.com>
Live Chat: http://www.internetworkexpert.com/chat/
<https://webmail.123together.com/exchweb/bin/redir.asp?URL=http://www.in
ternetworkexpert.com/chat/>
________________________________
From: nobody@groupstudy.com on behalf of Jay Hanke
Sent: Fri 11/24/2006 10:15 AM
To: ccielab@groupstudy.com
Subject: LLQ and bandwidth on ethernet interface
[demime could not interpret encoding quoted-printable - treating as
plain text]
When defining bandwidth percentages in LLQ setting the bandwidth on a
given Ethernet interface will adjust the calculated bandwidth
proportionally. LLQ doesn't do anything until there is congestion. So
when does congestion occur if the bandwidth is set below the interface
rate? Does it occur when the interface utilization exceeds the
provisioned bandwidth or does congestion occur at the interface line
rate?
This is the scenario that I have in mind:
Router1 Ethernet port =3D=3D> 1 mb/s Ethernet bridge =3D=3D> Router 2
Ethern=
et
port
Jay
------------------------------------------------------------------------
----=
---------=0A=
=0A=
The information contained in this e-mail message may contain privileged,
con=
fidential, and/or proprietary information intended to be protected from
publ=
ic disclosure. If you are not the intended recipient, any further
disclosure=
, use, dissemination, distribution, or copying of this message or any
attach=
ment is strictly prohibited. Unauthorized interception or disclosure of
this=
e-mail may violate certain laws and/or regulations, resulting in
criminal a=
nd/or civil prosecution. If you think that you have received this e-mail
mes=
sage in error, please delete it and notify the sender immediately.
This archive was generated by hypermail 2.1.4 : Fri Dec 01 2006 - 08:05:48 ART