[cisco-bba] 'sessions' versus 'PPPoA/E sessions' counts
ahmad fadly
peditea at yahoo.com
Fri Jun 5 03:29:24 EDT 2009
Hi Frank,
Based on my experience if the router is high in cpu process there will be a lot of pending sessions because router cannot handle the call. It happened in ppp session using l2TP. Usually the session will be jammed in the router. That's why there are lot of pending number of session.
Using CAC perhaps can protect the router from processing a lot of number of call. It will reject the call when cpu reach certain value (depend on our setting) instead of accept the call and process it. I assumed your number of mean call per minutes is high because cpu proc.
How many percent is your cpu proc?
I don't know if the problem will be the same as I had. Hope it can help you.
Here is the sample problem I had:
C_10K#sh sss statistics
Current Subscriber Statistics:
Number of sessions currently up: 70
Number of sessions currently pending: 928
Number of sessions currently authenticated: 70
Number of sessions currently unauthenticated: 928
Highest number of sessions ever up at one time: 10611
Mean up-time duration of sessions: 00:10:48
Total number of sessions up so far: 237972
Mean call rate per minute: 682, per hour: 47780
Number of sessions failed to come up: 175444
Access type based session count:
VPDN sessions = 998
Traffic-Class sessions = 140
C_10K#sh vpdn session state | i 00:00:
52591 1233 32679 -, - wiccn 00:00:09 0
19592 3585 32679 -, - wiccn 00:00:05 0
21825 209 32679 -, - wiccn 00:00:01 0
49333 2774 32679 -, - wiccn 00:00:01 0
6986 6068 32679 -, - wiccn 00:00:01 0
20031 6810 32679 -, - wiccn 00:00:01 0
44303 693 32679 -, - wiccn 00:00:01 0
16123 4342 32679 -, - wiccn 00:00:01 0
11714 3903 32679 -, - wiccn 00:00:09 0
51635 9267 32679 -, - wiccn 00:00:09 0
59529 7723 32679 -, - wiccn 00:00:09 0
5228 10439 32679 -, - wiccn 00:00:09 0
55820 2991 32679 -, - wiccn 00:00:09 0
49586 3899 32679 -, - wiccn 00:00:01 0
---
C_10K#sh proc cpu his
44455555333333333344444555551111 4
11111111777773333333333999994444 33333 77777111111
100
90
80
70
60 *****
50 ***** *****
40 ************* ********** *
30 **************************** *
20 **************************** *
10 ******************************** ***** *
0....5....1....1....2....2....3....3....4....4....5....5....
0 5 0 5 0 5 0 5 0 5
CPU% per second (last 60 seconds)
11
8380034444456434344644473346745547354475666544478999999999
2730013159128490980609559821084218756790224893684999999999
100 #* #########
90 #* #########
80 * *#* * * * **#########
70 * *## * * * * * * **#########
60 * *## * * * ** * * * **** **#########
50 * *## ** ** * * *** ***** * ********** **##########
40 #**## ******#***************#*********#*#*##**############
30 #*###***##################################################
20 ##########################################################
10 ##########################################################
0....5....1....1....2....2....3....3....4....4....5....5....
0 5 0 5 0 5 0 5 0 5
CPU% per minute (last 60 minutes)
* = maximum CPU% # = average CPU%
--
Fadly
--- On Fri, 6/5/09, Frank Bulk <frnkblk at iname.com> wrote:
> From: Frank Bulk <frnkblk at iname.com>
> Subject: RE: 'sessions' versus 'PPPoA/E sessions' counts
> To: "'ahmad fadly'" <peditea at yahoo.com>, cisco-bba at puck.nether.net, frnkblk at iname.com
> Date: Friday, June 5, 2009, 10:33 AM
> Thanks, but that doesn't solve the
> underlying issue of why I'm seeing so
> many call attempts.
>
> Frank
>
> -----Original Message-----
> From: ahmad fadly [mailto:peditea at yahoo.com]
>
> Sent: Thursday, June 04, 2009 8:43 PM
> To: cisco-bba at puck.nether.net;
> frnkblk at iname.com
> Subject: Re: 'sessions' versus 'PPPoA/E sessions' counts
>
>
> I seem too many pending and fail number of sessions. If you
> see your cpu
> proc is to high and your box is overly busy, try to use CAC
> (call admission
> control). It works to prevent overloading cpu and protect
> the router
> resources.
>
> You can use sh call admission statistics to see the CAC
> statistic
> C10K#sh call admission statistics
> Cac New Model (SRSM) is ACTIVE
> Total call Session charges: 0, limit 90
> Total calls rejected 1669, accepted 340854
> Reject reason: CPU-limit: 1669 SessionCharges 0
> Current actual CPU: 14%, Limit: 90%
> Hardware CAC is currently not active
>
> -----
> Fadly
>
> > Date: Thu, 04 Jun 2009 16:11:51 +0300
> > From: Tassos Chatzithomaoglou <achatz at forthnet.gr>
> > To: cisco-bba at puck.nether.net
> > Subject: Re: [cisco-bba] 'sessions' versus 'PPPoA/E
> > sessions' counts
> >
> > Number of sessions currently up + Number of sessions
> > currently pending = PPPoA + PPPoE
> >
> > PPPoA or PPPoE doesn't take into account whether the
> > sessions have finished their negotiation.
> >
> > --
> > Tassos
> >
> > Frank Bulk wrote on 04/06/2009 13:22:
> > > When I looked at my "sh subscriber statistics" I
> > noticed that
> > > - my "sessions currently up" does not add up to
> the
> > number of PPPoA and
> > > PPPoE sessions: how can that be?
> > > - I have a very high "Number of sessions failed
> to
> > come up"
> > > - my call rate is 3341/minute, which is
> 56/second
> > >
> > > I know I have lots of provisioned VP/VCs that
> don't
> > have an active DSLAM
> > > port, but I'm not sure if that contributes to an
> > explanation.
> > >
> > > If there's a debug I need to turn on to "see",
> please
> > suggest the
> > > appropriate one. It seems that the box is
> overly
> > busy.
> > >
> > > Frank
> > >
> > >
> >
> ==================================================================
> > > Router#sh subscriber statistics
> > >
> > > Current Subscriber Statistics:
> > >
> > > Number of sessions currently up: 2596
> > > Number of sessions currently pending: 1327
> > > Number of sessions currently authenticated: 2596
> > > Number of sessions currently unauthenticated:
> 1327
> > > Highest number of sessions ever up at one time:
> 2647
> > > Mean up-time duration of sessions: 00:01:08
> > > Total number of sessions up so far: 543761664
> > > Mean call rate per minute: 3341, per hour:
> 200502
> > > Number of sessions failed to come up: 543534572
> > > Access type based session count:
> > > PPPoA sessions = 3711
> > > PPPoE sessions = 212
> > >
>
>
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