Поиск по этому блогу

13.01.2010

Тестирование E1

В заметке описывается организация тестирования потоков E1 для поиска неисправности. Приводятся примеры установки петли (loopback) на контроллере E1 маршрутизатора Cisco, проведение BERT-тестов с использованием функционала Cisco IOS.
Имеем схему, где с одной стороны маршрутизатор с VWIC2-1MFT-T1/E1, а с другой - маршрутизатор с v.35 интерфейсом, включенный в мультиплексор.



Чтобы установить петлю на контроллере E1 необходимо выполнить ряд команд:
controller E1 0/3/0
framing NO-CRC4
channel-group 1 timeslots 1-16

router1(config)#controller E1 0/3/0
router1(config-controller)#loopback local line
Чтобы протестировать канал на втором маршрутизаторе необходимо поставить инкапсуляцию HDLC и прописать любой адрес, который далее будет пинговаться.
router2#ping 1.1.1.1 time 4 repe 500 siz 2000 val

Type escape sequence to abort.
Sending 500, 2000-byte ICMP Echos to 1.1.1.1, timeout is 4 seconds:
Reply data will be validated
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!
Success rate is 100 percent (500/500), round-trip min/avg/max =
208/810/3692 ms

router2#show interface serial3/3
Serial3/3 is up, line protocol is up (looped)
Hardware is DSCC4 Serial
Description: To router 1
Internet address is 1.1.1.1/30
MTU 1500 bytes, BW 1024 Kbit, DLY 20000 usec,
reliability 255/255, txload 3/255, rxload 3/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:00:06, output 00:00:06, output hang never
Last clearing of "show interface" counters 00:08:58
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 14000 bits/sec, 0 packets/sec
30 second output rate 13000 bits/sec, 0 packets/sec
2075 packets input, 2033944 bytes, 0 no buffer
Received 65 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
2075 packets output, 2033944 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 output buffer failures, 0 output buffers swapped out
2 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up

Видно, что ошибок нет, но задержка подозрительно большая и плавает, когда должна быть в пределах 100мс для данного канала. Аналогичный заворот в сторону router1 на ближайнем к нему мультиплексоре E1 дает гораздо меньшие задержки
router1#ping 1.1.1.1 rep 1000

Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/3/20 ms

router1#show run int Serial0/3/0:1
Building configuration...
Current configuration : 108 bytes
!
interface Serial0/3/0:1
ip address 1.1.1.1 255.255.255.252
no fair-queue
end

router1#sh int Serial0/3/0:1
Serial0/3/0:1 is up, line protocol is up (looped)
Hardware is GT96K Serial
Description: To router 2
Internet address is 1.1.1.1/30
MTU 1500 bytes, BW 1024 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:00:05, output 00:00:05, output hang never
Last clearing of "show interface" counters 01:05:33
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 6000 bits/sec, 8 packets/sec
5 minute output rate 6000 bits/sec, 8 packets/sec
2469 packets input, 241506 bytes, 0 no buffer
Received 459 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
2469 packets output, 241506 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
Timeslot(s) Used:1-16, SCC: 0, Transmitter delay is 0 flags

Проблема была решена сменой порта router2 и мультиплексора, куда он был включен. В итоге задержки на канале были на уровне 70мс, вместо плавающих 100-XXXXмс.

Помимо описанной выше проблемы, ранее возникает ситуация, при которой CRC ошибки возникают только на интерфейсе router1. На router2 никаких ошибок не возникает и петля на контроллере E1 (router1) не дает никаких ошибок, как на router1:
E1 0/3/0 is up.
Applique type is Channelized E1 - balanced
Cablelength is Unknown
No alarms detected.
alarm-trigger is not set
Version info Firmware: 20090408, FPGA: 13, spm_count = 0
Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line.
Data in current interval (56 seconds elapsed):
0 Line Code Violations, 33 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Total Data (last 1 15 minute intervals):
0 Line Code Violations, 68 Path Code Violations,
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

Serial0/3/0:1 is up, line protocol is up
Hardware is GT96K Serial
Description: To router 2
MTU 1500 bytes, BW 1024 Kbit/sec, DLY 20000 usec,
reliability 245/255, txload 1/255, rxload 1/255
Encapsulation FRAME-RELAY, loopback not set
Keepalive set (10 sec)
LMI enq sent 98, LMI stat recvd 98, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 1023 LMI type is CISCO frame relay DTE
FR SVC disabled, LAPF state down
Broadcast queue 0/64, broadcasts sent/dropped 16/0, interface broadcasts 0
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:16:16
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 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
327 packets input, 20614 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
905 input errors, 453 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
114 packets output, 6922 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
Timeslot(s) Used:1-16, SCC: 0, Transmitter delay is 0 flags


Далее при установке петли на мультиплексоре со стороны router2 на интерфейсе router1 возникают ошибки, которые можно проверить BERT тестером на router1
router1#show interface se 0/3/0:1
Serial0/3/0:1 is up, line protocol is up (looped)

router1# bert controller e1 0/3/0 channel-group 1 interval 5
Просмотр статистики в процессе измерения:
router1#show controllers e1 0/3/0 bert
E1 0/3/0 is up.
BERT is in progress on channel-group 1. The result of last time is
DSX1 BERT status : sync
DSX1 BERT pattern : QRSS
DSX1 BERT sync count : 1
DSX1 BERT interval : 5 min
DSX1 BERT time remain : 1 min 44 sec
DSX1 BERT total errs : 9
DSX1 BERT total k bits: 2769
DSX1 BERT errors (last): 9
DSX1 BERT k bits (last): 2769
Просмотр статистики по завершению измерения:
router1#show controllers e1 0/3/0 bert
E1 0/3/0 is up.
BERT is done on channel-group 1. The result of last time is
DSX1 BERT status : done
DSX1 BERT pattern : QRSS
DSX1 BERT sync count : 1
DSX1 BERT interval : 5 min
DSX1 BERT time remain : 0 min 0 sec
DSX1 BERT total errs : 12
DSX1 BERT total k bits: 4231
DSX1 BERT errors (last): 12
DSX1 BERT k bits (last): 4231

Кстати, одновременно запустить еще один тест для другой группы нельзя.
router1# bert controller e1 0/3/0 channel-group 2 interval 5
% Bert hardware in use - command refused

После проведенных работ на оборудовании оператора BERT тест не показывает ошибок
router1#show controllers e1 0/3/0 bert
E1 0/3/0 is up.
BERT is done on channel-group 1. The result of last time is
DSX1 BERT status : done
DSX1 BERT pattern : QRSS
DSX1 BERT sync count : 1
DSX1 BERT interval : 10 min
DSX1 BERT time remain : 0 min 0 sec
DSX1 BERT total errs : 0
DSX1 BERT total k bits: 256538
DSX1 BERT errors (last): 0
DSX1 BERT k bits (last): 256538

Ошибки Path Code Violations на контроллере больше не появляются
E1 0/3/0 is up.
Applique type is Channelized E1 - balanced
Cablelength is Unknown
No alarms detected.
alarm-trigger is not set
Version info Firmware: 20090408, FPGA: 13, spm_count = 0
Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line.
Data in current interval (273 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

Отдельно замечу, что поскольку на router1 два контроллера E1, то необходимо сконфигрурировать источник синхронизации. В данном случае синхронизация берется из линии 0/3/0
router1#show network-clocks
Network Clock Configuration
---------------------------
Priority Clock Source Clock State Clock Type

2 E1 0/3/0 GOOD E1
3 E1 0/1/0 GOOD E1
11 Backplane GOOD PLL

Current Primary Clock Source
---------------------------
Priority Clock Source Clock State Clock Type

2 E1 0/3/0 GOOD E1
Выбор источника синхронизации для маршрутизатора зависит от наличия карт E1 и от того, в какой слот они установлены. Можно задавать приоритеты выбора источника:
network-clock-participate wic 1
network-clock-participate wic 3
network-clock-select 2 E1 0/3/0
network-clock-select 3 E1 0/1/0