[cisco-nas] 96K availainle bandwidth vs 128K BW on Vi1 bundle consisting of 2 B-channels during 64K Unrestrictet call via ISDN-TA PPP-multilink to 5350 NAS

[&y0]

 According to customer he connects to COM1 with DTE rate of 112K (what is
the standard of async rate???). Ok. But ~96K (as it can be seen from flood
ping result below) is not 112K. Additional bandwidth in 112-96=16K just
desappears :O) Why?

 Router#sh int virtual-access 1 | i rate|drop
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 7940
  Queueing strategy: weighted fair
  Output queue: 64/1000/64/7940 (size/max total/threshold/drops)
  30 second input rate 91000 bits/sec, 10 packets/sec
  30 second output rate 124000 bits/sec, 12 packets/sec  
Note customer cant make flood ping so I did it from my router and as I
understand I must have near equal amount of input traffic to output one. 

> -----Original Message-----
> From: Tassos Chatzithomaoglou [mailto:achatz at forthnet.gr] 
> Sent: Friday, January 28, 2005 2:41 PM
> To: andyo at grass.org.ua
> Cc: cisco-nas at puck.nether.net
> Subject: Re: [cisco-nas] 96K availainle bandwidth vs 128K BW 
> on Vi1 bundle consisting of 2 B-channels during 64K 
> Unrestrictet call via ISDN-TA PPP-multilink to 5350 NAS
> 
> If the ISDN-TA is connected to the user's PC though a serial 
> (115200) port, then this might be "logical".
> 
> &y0 wrote on 28/1/2005 1:51 ??:
> > Hi everybody. I have problem while customers places calls 
> to 5350 NAS 
> > via ISDN using ISDN-TA and PPP-multilink. During the call 2 
> B-channels 
> > are bound to Virtual-access interface which parameters then 
> looks like this:
> > Router#sh int virtual-access 1
> > Virtual-Access1 is up, line protocol is up
> >   Hardware is Virtual Access interface
> >   MTU 1500 bytes, BW 128 Kbit, DLY 100000 usec,
> >      reliability 255/255, txload 1/255, rxload 7/255
> >   Encapsulation PPP, loopback not set
> >   DTR is pulsed for 5 seconds on reset
> >   Time to interface disconnect:  idle 3w3d
> >   LCP Open, multilink Open
> >   Open: IPCP
> >   Last input 00:00:00, output never, output hang never
> >   Last clearing of "show interface" counters 02:28:22
> >   Input queue: 0/75/0/0 (size/max/drops/flushes); Total 
> output drops: 0
> >   Queueing strategy: weighted fair
> >   Output queue: 0/1000/64/0 (size/max total/threshold/drops)
> >      Conversations  0/50/256 (active/max active/max total)
> >      Reserved Conversations 0/0 (allocated/max allocated)
> >      Available Bandwidth 96 kilobits/sec
> >   30 second input rate 4000 bits/sec, 2 packets/sec
> >   30 second output rate 1000 bits/sec, 1 packets/sec
> >      32892 packets input, 15179159 bytes, 0 no buffer
> >      Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
> >      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
> >      31164 packets output, 18584822 bytes, 0 underruns
> >      0 output errors, 0 collisions, 0 interface resets
> >      0 output buffer failures, 0 output buffers swapped out
> >      0 carrier transitions
> > Router#sy
> >   Interface      User        Mode                     Idle  
>    Peer Address
> >   Vi1          fim        Virtual PPP (Bundle) 00:00:06 10.2.2.1
> >   Se3/0:1      fim        Sync PPP                    -   
> Bundle: Vi1
> >   Se3/0:2      fim        Sync PPP                    -   
> Bundle: Vi1
> > Accordingly customer can obtain the data transfer speed no 
> more ~88K.
> > It looks like 16K is spent for unknown reason per each B-channel as 
> > arithmetic of 2*(64K-16K)=96K shows I have ever trusted that 
> > signalling bandwidth should be taken from D-channel 
> bandwidth (in my 
> > case Serial3/0:15).
> > Am I correct? Have anybody solution for this problem? Below is 
> > configuration of ISDN and D-channel isdn switch-type primary-net5 
> > controller E1 3/0 framing NO-CRC4  pri-group timeslots 1-31 
> interface 
> > Serial3/0:15  ip unnumbered FastEthernet0/0  ip nat inside  
> > encapsulation ppp  load-interval 30  dialer idle-timeout 2147483  
> > dialer load-threshold 1 outbound dialer-group 1  autodetect 
> > encapsulation ppp v120  isdn switch-type
> > primary-net5  isdn incoming-voice modem  isdn 
> sending-complete  no cdp 
> > enable  ppp authentication pap contract_tac  ppp authorization 
> > contract_tac ppp multilink  ppp timeout multilink link add 1
> > 
> > --
> > AO618-RIPE
> > 108248909
> > 
> > _______________________________________________
> > cisco-nas mailing list
> > cisco-nas at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-nas
>