I have recently setup a link between two Cisco 3640's each with a 4T1 IMA
card. This is a back-to-back setup, with no true ATM switch in the middle,
just 4 T1's from the phone company. This link should be 6mbps, however,
with overhead, I would expect for it to be around 5mbps. The problem is,
that in testing, I am only seeing about 3mbps through this link. I find
that to be unreasonably low. I have included below the configuration and
diagnostics output for these two routers.
There is a line in the 'show atm interface atm 2/0, 2/1, 2/2, 2/3" command
that reports the available bandwidth as 1mbps. This seems odd to me.
Does anyone have any ideas or any experience with Cisco IMA?
Router 1:
interface ATM2/0
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
clock source internal
no scrambling-payload
cablelength short 133
!
interface ATM2/1
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
clock source internal
no scrambling-payload
cablelength short 133
!
interface ATM2/2
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
clock source internal
no scrambling-payload
cablelength short 133
!
interface ATM2/3
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
clock source internal
no scrambling-payload
cablelength short 133
!
interface ATM2/IMA0
ip address 192.168.1.1 255.255.255.252
no ip directed-broadcast
no atm ilmi-keepalive
pvc 0/33
encapsulation aal5snap
!
!
3640-1#show atm pvc
VCD / Peak Avg/Min Burst
Interface Name VPI VCI Type Encaps SC Kbps Kbps Cells
Sts
2/IMA0 1 0 33 PVC SNAP UBR 6000
UP
3640-1#
Cisco-1#show ima interface
Interface ATM2/IMA0 is up
Group index is 1
Ne state is operational, failure status is noFailure
Active links bitmap 0xF
IMA Group Current Configuration:
Tx/Rx configured links bitmap 0xF/0xF
Tx/Rx minimum required links 1/1
Maximum allowed diff delay is 25ms, Tx frame length 128
Ne Tx clock mode CTC, configured timing reference link ATM2/0
Test pattern procedure is disabled
IMA Group Current Counters (time elapsed 293 seconds):
0 Ne Failures, 0 Fe Failures, 0 Unavail Secs
IMA Group Total Counters (last 24 hours):
0 Ne Failures, 0 Fe Failures, 0 Unavail Secs
IMA link Information:
Link Physical Status NearEnd Rx Status Test Status
---- --------------- ----------------- -----------
ATM2/0 up active disabled
ATM2/1 up active disabled
ATM2/2 up active disabled
ATM2/3 up active disabled
Cisco-1#
3640-1#show atm interface atm 2/0
Interface ATM2/0:
AAL enabled: AAL5 , Maximum VCs: 256, Current VCCs: 0
Maximum Transmit Channels: 0
Max. Datagram Size: 4496
PLIM Type: DS1, Framing is T1 ESF, TX clocking: INTERNAL
Cell-payload scrambling: OFF
0 input, 0 output, 0 IN fast, 0 OUT fast, 0 out drop
Avail bw = 1000 ***** NOTE: ONLY 1mbps? *****
Config. is ACTIVE
Cisco-1#
Router 2:
interface ATM2/0
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
no scrambling-payload
cablelength short 133
!
interface ATM2/1
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
no scrambling-payload
cablelength short 133
!
interface ATM2/2
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
no scrambling-payload
cablelength short 133
!
interface ATM2/3
no ip address
no ip directed-broadcast
no atm ilmi-keepalive
ima-group 0
no scrambling-payload
cablelength short 133
!
interface ATM2/IMA0
ip address 192.168.1.2 255.255.255.252
no ip directed-broadcast
no atm ilmi-keepalive
pvc 0/33
encapsulation aal5snap
!
Brian Pavane
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:17 EDT