nanog mailing list archives

Re: PPP multilink help


From: Dan White <dwhite () olp net>
Date: Mon, 11 May 2009 09:54:29 -0500

Andrey Gordon wrote:
Hey folks, I'm sure to you it's peanuts, but I'm a bit puzzled (most likely
because of the lack of knowledge, I bet).

I'm buying an IP backbone from VNZ (presumably MPLS). I get a MLPPP hand off
on all sites, so I don't do the actual labeling and switching, so I guess
for practical purposes what I'm trying to say is that I have no physical
control over the other side of my MLPPP links.

When I transfer a large file over FTP (or CIFS, or anything else), I'd
expect it to max out either one or both T1, but instead utilization on the
T1s is hoovering at 70% on both and sometimes MLPPP link utilization even
drops below 50%. What am I'm not gettting here?

I seem to be in a similar situation as you (but with AT&T). I have not noticed any unexpected missing bandwidth.

I don't see any specific problems with your config, but I'll include mine in hopes it will be useful:

controller T1 0/0/0
framing esf
linecode b8zs
channel-group 0 timeslots 1-24
!
controller T1 0/0/1
framing esf
linecode b8zs
channel-group 0 timeslots 1-24
!
class-map match-any imaging
match access-group 112
class-map match-any rdp
match access-group 113
class-map match-any voice
match ip dscp ef
match access-group 110
!
policy-map private_wan
class voice
 priority percent 60
 set ip dscp ef
class rdp
 bandwidth percent 32
 set ip dscp af31
class imaging
 bandwidth percent 4
 set ip dscp af21
class class-default
 bandwidth percent 4
 set ip dscp default
!
interface Multilink1
ip address x.x.x.38 255.255.255.252
no keepalive
no cdp enable
ppp chap hostname xxxxxxx
ppp multilink
ppp multilink fragment disable
ppp multilink group 1
max-reserved-bandwidth 100
service-policy output private_wan
!
interface Serial0/0/0:0
no ip address
encapsulation ppp
no cdp enable
ppp chap hostname xxxxxxxxxx
ppp multilink
ppp multilink group 1
max-reserved-bandwidth 100
!
interface Serial0/0/1:0
no ip address
encapsulation ppp
no cdp enable
ppp chap hostname xxxxxxxxxx
ppp multilink
ppp multilink group 1
max-reserved-bandwidth 100
!
access-list 110 permit ip any 10.0.0.0 0.0.255.255
access-list 110 permit ip 10.0.0.0 0.0.255.255 any
access-list 110 permit icmp any any
access-list 112 permit ip any host x.x.x.x
access-list 113 permit ip any host x.x.x.x



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