[c-nsp] 2811 performance on an Ethernet over SONET connection??

[Joe Freeman]

I tried both straight rate-limiting and traffic policing with no change in
symptoms.

On 2/15/08, Paolo Lucente <pl+list at pmacct.net> wrote:
>
> Hi Joe,
>
> it might be you need to apply some outbound shaping onto the interface
> facing
> the Internet due to the difference between the access rate (100Mbps) and
> the
> CIR (15Mbps). This could explain why degraded throughput is experienced
> only
> upstream. I can't really imagine it could be a CPU-related issue, but all
> in
> all it's worth checking it.
>
> Cheers,
>
> Paolo
>
>
>
> On Fri, Feb 15, 2008 at 02:59:55PM -0600, Joe Freeman wrote:
> > Folks-
> >
> > I have a situation in which a customer has a 2811 router connected to an
> > Ethernet over SONET pipe from me onto which he subscribes 15M of
> Internet.
> > The SONET portion of the pipe currently has 11 VT1.5's cross-connected.
> This
> > customer is seeing asymmetric performance on the link in that his upload
> > speeds are significantly lower than the download speeds.
> >
> > Given that there is no congestion on the network, plenty of bandwidth is
> > available, and no significant packet/frame loss errors are seen at any
> > point, including on the SONET ADM boxes, I'm sort of at a loss. Further,
> I
> > can plug my laptop into this port with 1323 opts, nagle, window scaling,
> and
> > a large MAX window size and test absolutely fine across the circuit. I
> plug
> > the same laptop into the lan side of his router (Fa0/1, below) and I see
> the
> > significant drop of which he's complaining.
> >
> > I've also verified the speed/duplex settings are appropriate and are
> working
> > correctly. One other thing I've noticed is that as I increase bandwidth
> > across the SONET ring, the disconnect between upload and download speeds
> > appears to grow on an almost log scale.
> >
> > Anyone have any thoughts or tips on this?
> >
> > Thanks-
> > Joe
> >
> > R1#sho ver
> > Cisco IOS Software, 2800 Software (C2800NM-IPBASE-M), Version 12.4(3d),
> > RELEASE SOFTWARE (fc3)
> > Technical Support: http://www.cisco.com/techsupport
> > Copyright (c) 1986-2006 by Cisco Systems, Inc.
> > Compiled Wed 19-Apr-06 09:18 by alnguyen
> >
> > ROM: System Bootstrap, Version 12.4(1r) [hqluong 1r], RELEASE SOFTWARE
> (fc1)
> >
> > nettech uptime is 1 hour, 23 minutes
> > System returned to ROM by power-on
> > System image file is "flash:c2800nm-ipbase-mz.124-3d.bin"
> >
> > Cisco 2811 (revision 53.51) with 251904K/10240K bytes of memory.
> > Processor board ID FTX1027A1HS
> > 6 FastEthernet interfaces
> > DRAM configuration is 64 bits wide with parity enabled.
> > 239K bytes of non-volatile configuration memory.
> > 62720K bytes of ATA CompactFlash (Read/Write)
> >
> > Configuration register is 0x2102
> >
> > R1#sho run
> > Building configuration...
> >
> > Current configuration : 1115 bytes
> > !
> > version 12.4
> > service timestamps debug datetime msec
> > service timestamps log datetime msec
> > no service password-encryption
> > !
> > hostname R1
> > !
> > boot-start-marker
> > boot-end-marker
> > !
> > !
> > no aaa new-model
> > !
> > resource policy
> > !
> > ip subnet-zero
> > !
> > !
> > ip cef
> > !
> > !
> > no ip domain lookup
> > ip domain name R1.net
> > !
> > !
> > !
> > !
> > interface FastEthernet0/0
> >  description to Internet
> >  ip address 66.211.51.10 255.255.255.252
> >  ip nat outside
> >  load-interval 30
> >  duplex auto
> >  speed auto
> > !
> > interface FastEthernet0/1
> >  description To LAN
> >  ip address 192.168.1.1 255.255.255.0
> >  ip nat inside
> >  duplex auto
> >  speed auto
> > !
> > interface FastEthernet0/0/0
> > !
> > interface FastEthernet0/0/1
> > !
> > interface FastEthernet0/0/2
> > !
> > interface FastEthernet0/0/3
> > !
> > interface Vlan1
> >  no ip address
> > !
> > ip classless
> > ip route 0.0.0.0 0.0.0.0 66.211.51.9
> > !
> > no ip http server
> > ip nat inside source static 192.168.1.2 interface FastEthernet0/0
> > !
> > !
> > control-plane
> > !
> > banner motd ^C Authorized personel only, please. ^C
> > !
> > line con 0
> > line aux 0
> > line vty 0 4
> >  password cisco
> >  login
> > !
> > scheduler allocate 20000 1000
> > !
> > end
>
>