08-30-2006 12:42 PM - edited 03-03-2019 01:49 PM
Any reason a 3640 with an NM-A1-T3 couldn't handle a ds-3 circuit? We have a 10mb pvc on it which I believe can burst upto the full ds-3 speed. We seem to be losing UDP packets at the application level at a rate of about 5-10 per minute under steady load.
Here is the output from show interface:
Cisco#show interface atm 1/0
ATM1/0 is up, line protocol is up
Hardware is RS8234 ATM DS3
MTU 4470 bytes, sub MTU 4470, BW 45000 Kbit, DLY 190 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ATM, loopback not set
Encapsulation(s): AAL5
1023 maximum active VCs, 1 current VCCs
VC Auto Creation Disabled.
VC idle disconnect time: 300 seconds
Last input 00:00:00, output 00:00:01, output hang never
Last clearing of "show interface" counters 03:25:56
Input queue: 0/200/40/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: Per VC Queueing
5 minute input rate 27000 bits/sec, 20 packets/sec
5 minute output rate 2000 bits/sec, 2 packets/sec
856451 packets input, 156468990 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
139135 packets output, 8915907 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
The drops (40) from the input queue don't seem to coorespond to the udp packets that application is not receiving. I think the drops are in the network or on this router as I have the same data and application working on another circuit (ima atm with 3 T1s) working with only a few dropped packets a day and I can trace this to data bursts that exceed the 4.5mb bandwidth.
I'm trying to figure out if the loss in in the atm cloud or at my router. Any thoughts on how to proceed would be appriciated. -- Bud
08-30-2006 03:49 PM
3640's are old, slow routers. While it can accommodate a DS3 card, dont expect it to be able to even get close to filling it up. While I dont have hard numbers on how much it can push, i'd estimate you'll max out at about 8-10Mbps.
In order to push a full DS3, you'll need a 3825 if you aren't running any features (qos), and a 3845 if you are.
Make sure you have 'ip cef' enabled globally, and there isn't any 'no ip route-cache' on any of your interfaces in order to get the most performance out of your router.
08-31-2006 06:56 AM
Thanks wochanda for some feedback. I have confirmed that others are using the same hardware for this application and aren't seeing dropped packets so I am now more confident that it is a configuration issue or bad piece of hardware. We basically have a fast ethernet interface and a DS3/ATM module:
Cisco#show hardware
Cisco Internetwork Operating System Software
IOS (tm) 3600 Software (C3640-JS-M), Version 12.3(17a), RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Mon 12-Dec-05 16:29 by evmiller
Image text-base: 0x60008B00, data-base: 0x61F08000
ROM: System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)
ROM: 3600 Software (C3640-JS-M), Version 12.3(17a), RELEASE SOFTWARE (fc2)
Cisco uptime is 17 hours, 15 minutes
System returned to ROM by power-on
System image file is "flash:c3640-js-mz.123-17a.bin"
cisco 3640 (R4700) processor (revision 0x00) with 124928K/6144K bytes of memory.
Processor board ID 26878521
R4700 CPU at 100MHz, Implementation 33, Rev 1.0
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
1 FastEthernet/IEEE 802.3 interface(s)
1 ATM network interface(s)
DRAM configuration is 64 bits wide with parity disabled.
125K bytes of non-volatile configuration memory.
32768K bytes of processor board System flash (Read/Write)
Configuration register is 0x2102
08-31-2006 07:03 AM
Cisco#show control atm 1/0
Interface ATM1/0 is up
Hardware is RS8234 ATM DS3
LANE client MAC address is 0008.2156.0b50
hwidb=0x634920D8, ds=0x634938A4
RS8234 base 3C800000, ds 634938A4, PM5346 base 3CC00000, slave base 3CC00000
SBDs - avail 2048, guaranteed 1, unguaranteed 2047, starved 0 rbds 4098
Seg VCC SCH access timeout 0
[snip]
PCI bus err 0, DMA fifo full err 0, RSM parity err 0
RSM sync err 0, RSM/SEG Q full err 0, RSM overflow err 0
RSM stat Q full err 0, no free buff Q err 0, RSM ignore rbd CPI count 0
RSM ignore rbd CPI&PAD count 0, RSM ignore rbd abort count 0
RSM ignore rbd unknown count 0, pdu_check flag 0x0, error flag 0x0
SEG stat Q full err 0, SEG underflow err 0
Framer Chip Type PM7345
Framer Chip ID 0x20
Framer State RUNNING
Defect Status NO ERRORS
Loopback Mode NONE
Clock Source INTERNAL (but the source of this clock is derived from LINE)
DS3 Scrambling ON
Framing DS3 C-bit direct mapping
TX cells 1392577
TX bytes 73806581
Last output time 17:10:48
RX cells 9659689
RX bytes 511963517
Last input time 17:10:48
Line Code Violations (LCV) 198
DS3: F/M-bit errors 0
DS3: parity errors 30
DS3: path parity errors 30
DS3/E3: G.832 FEBE errors 10
T3/E3: excessive zeros 121
uncorrectable HEC errors 13
idle/unassigned cells dropped 0
LCV errored secs 6
DS3: F/M-bit errored secs 0
DS3: parity errored secs 6
DS3: path parity errored secs 6
T3/E3: excessive zeros errored secs 6
DS3/E3: G.832 FEBE errored secs 1
uncorrectable HEC errored secs 4
LCV error-free secs 61825
DS3: F/M-bit error-free secs 61831
DS3: parity error-free secs 61825
DS3: path parity error-free secs 61825
T3/E3: excessive zeros error-free secs 61825
DS3/E3: G.832 FEBE error-free secs 61830
uncorrectable HEC error-free secs 61827
PM 7345 registers (base 0x3CC00000):
[snip]
The errors that show up here don't seem to correspond to the drops I am seeing. In other words, these counts don't change when I am seeing dropped packets.
08-31-2006 07:08 AM
Here is my running config:
Cisco#show run
Building configuration...
Current configuration : 1848 bytes
!
version 12.3
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname Cisco
!
boot-start-marker
boot-end-marker
!
logging buffered 20000 debugging
enable secret xxxxxx
!
no aaa new-model
ip subnet-zero
ip tcp synwait-time 5
!
!
no ip domain lookup
!
no ip bootp server
ip multicast-routing
ip cef
!
buffers small permanent 200
buffers small max-free 300
buffers middle permanent 300
buffers middle max-free 500
!
interface Loopback0
no ip address
shutdown
!
interface FastEthernet0/0
description HPH LAN segment
ip address 172.21.x.x 255.255.255.224
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim neighbor-filter PIMFilter
ip pim sparse-mode
no ip mroute-cache
speed 100
full-duplex
no cdp enable
!
interface ATM1/0
no ip address
atm scrambling cell-payload
no atm ilmi-keepalive
hold-queue 200 in
!
interface ATM1/0.1 point-to-point
description PVC
ip address 172.20.x.x 255.255.255.252
ip pim sparse-mode
pvc 1/40
oam-pvc manage 30
oam ais-rdi 30 3
encapsulation aal5snap
!
!
no ip http server
ip classless
ip route 65.x.x.0 255.255.255.0 172.20.x.x
ip route 204.x.x.0 255.255.255.0 172.20.x.x
!
ip pim bidir-enable
ip pim rp-address 65.x.x.x THE_WAN
ip pim spt-threshold infinity
!
ip access-list standard PIMFilter
deny any
ip access-list standard THE_WAN
permit 233.x.x.0 0.0.0.63
deny any
no logging trap
no cdp run
!
line con 0
exec-timeout 0 0
login
line aux 0
login
transport input all
line vty 0
exec-timeout 120 0
password xxxxx
logging synchronous
login
length 0
line vty 1 4
exec-timeout 120 0
password xxxxx
logging synchronous
login
!
!
end
08-31-2006 07:25 AM
Two more notes. 98% of the traffic is multicast data coming into the DS3 interface. "show proc cpu hist" shows peek of 20% while packets are being dropped.
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