Strange ppp multilink speed issue

[phydoux999]

I have a customer using ppp multilink with two T-1s on a Cisco 1721. Running 12.3(16) firmware, 32meg flash 32 meg NVRAM. My customer is accessing a secure

http://www site,

that with both T-1s connected the

http://www site

is very, very slow. When my customer disconnects one of the T-1s(it does not matter which T-1) the speed of the

http://www site

increases 90%.

As I said it does not matter which T-1 is disconnected, the speed changes are the same. We have worked with the

http://www site

admins who state they do not see anything wrong. One of my admins suggested upgrading the firmware on the 1720 from 12.2(6c) to the current 12.3(16). This change actualy made the speed worse.

Any suggestions???

 

[NetworkGhost]

Well to start you could always do a sh mem and show processes cpu history. Check it out with both T1s and one T1. It is odd to see a performance decrease. Possibly a card issue? Are you using a 2 port WIC? Do you have a spare?

 

[phydoux999]

We have swapped both WICs and the 1721 itself. When we upgraded to the 12.3(16) firmware the performance dropped. We have also had both of the T-1s re-engineered by the LEC involved.

 

[ADB100]

If the performance dropped after upgrading to 12.3(16) then I would downgrade them and re-test if the problem goes away then raise a TAC case and get Cisco to look into it for you.

Andy

 

[NetworkGhost]

I would have your telco troubleshoot their end. If you arent seeing your processor or memory being taxed to badly with the second T1 then it would seem the distant end would have to be having an issue with the multi link. Maybe configuration issue/ Can you post your config?

 

[KiscoKid]

Could you possibly include a copy of the 1721 configuration. Also I'd be interested to see the output of 'show int xxx' when the slowness is occuring (where xxx is your multilink interface). I'd also like to see output from 'show ppp multilink'.

 

[phydoux999]

Well I am the telco/LEC on this. Here is the logs from the 1702.

Here is the configs of the interfaces and the sh inter...

interface Multilink1
ip unnumbered FastEthernet0
no cdp enable
ppp multilink
ppp multilink fragment disable
ppp multilink group 1
!
interface Serial0
no ip address
encapsulation ppp
no ip route-cache cef
no ip route-cache
no fair-queue
ppp multilink
ppp multilink group 1
!
interface Serial1
no ip address
encapsulation ppp
no ip route-cache cef
no ip route-cache
no fair-queue
ppp multilink
ppp multilink group 1
!
ip classless
ip route 0.0.0.0 0.0.0.0 Multilink1

Multilink1 is up, line protocol is up
Hardware is multilink group interface
Interface is unnumbered. Using address of FastEthernet0 (XXX.XXX.XXX.XXX)
MTU 1500 bytes, BW 3088 Kbit, DLY 100000 usec,
reliability 255/255, txload 16/255, rxload 91/255
Encapsulation PPP, LCP Open, multilink Open
Open: IPCP, loopback not set
Keepalive set (10 sec)
DTR is pulsed for 2 seconds on reset
Last input 00:00:00, output never, output hang never
Last clearing of "show interface" counters 00:28:28
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1104000 bits/sec, 149 packets/sec
5 minute output rate 205000 bits/sec, 122 packets/sec
279256 packets input, 266729664 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
220621 packets output, 48957234 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions

Serial0 is up, line protocol is up
Hardware is PQUICC with Fractional T1 CSU/DSU
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 15/255, rxload 99/255
Encapsulation PPP, LCP Open, multilink Open, loopback not set
Keepalive set (10 sec)
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:30:35
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 600000 bits/sec, 84 packets/sec
5 minute output rate 95000 bits/sec, 67 packets/sec
151937 packets input, 145521402 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
120442 packets output, 26798951 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

Serial1 is up, line protocol is up
Hardware is PQUICC with Fractional T1 CSU/DSU
MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,
reliability 255/255, txload 16/255, rxload 98/255
Encapsulation PPP, LCP Open, multilink Open, loopback not set
Keepalive set (10 sec)
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:30:35
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 598000 bits/sec, 86 packets/sec
5 minute output rate 98000 bits/sec, 67 packets/sec
151871 packets input, 145533843 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
120027 packets output, 26619154 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

Multilink1, bundle name is xxxxxxx
Bundle up for 01:27:12, 11/255 load
Receive buffer limit 24384 bytes, frag timeout 1000 ms
0/0 fragments/bytes in reassembly list
0 lost fragments, 55539 reordered
0/0 discarded fragments/bytes, 0 lost received
0xD3B71 received sequence, 0xB56ED sent sequence
Member links: 2 active, 0 inactive (max not set, min not set)
Se1, since 01:27:12
Se0, since 01:27:08

 

[NetworkGhost]

Have you tried enabling CEF and your IP route cache for your interfaces?