QoS | Queueing Strategy ex. fifo (part 2)

This is example real condition about fifo & WFQ in example Serial interface on Cisco router.

#sh run int s2/0:1
Building configuration...

Current configuration : 187 bytes
!
interface Serial2/0:1
description Back-to-Back-Serial
bandwidth 256
ip address 1.2.3.1 255.255.255.252
no fair-queue
end

#sh int s2/0:1
Serial2/0:1 is up, line protocol is up
Hardware is Multichannel E1
Description: Back-to-Back-Serial
Internet address is 1.2.3.1/30
MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec,
reliability 255/255, txload 242/255, rxload 139/255
Encapsulation HDLC, crc 16, Data non-inverted
Keepalive set (10 sec)
Last input 00:00:04, output 00:00:00, output hang never
Last clearing of "show interface" counters 4w1d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 913214
Queueing strategy: fifo
Output queue: 33/40 (size/max)
5 minute input rate 140000 bits/sec, 49 packets/sec
5 minute output rate 253000 bits/sec, 44 packets/sec
41308979 packets input, 1295718610 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
3 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 3 abort
43053273 packets output, 1159905965 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
no alarm present
Timeslot(s) Used:5-8, subrate: 64Kb/s, transmit delay is 0 flags

#ping 1.2.3.2 repeat 100
Type escape sequence to abort.
Sending 100, 100-byte ICMP Echos to 1.2.3.2, timeout is 2 seconds:
!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!.!!!!!!!!!!!!!....!!!!!!!!!!!
Success rate is 94 percent (94/100), round-trip min/avg/max = 316/1066/1552 ms

#conf t
Enter configuration commands, one per line. End with CNTL/Z.
(config)#int s2/0:1
(config-if)#fair-queue
(config-if)#^Z

#sh int s2/0:1
Serial2/0:1 is up, line protocol is up
Hardware is Multichannel E1
Description: Back-to-Back-Serial
Internet address is 1.2.3.1/30
MTU 1500 bytes, BW 256 Kbit, DLY 20000 usec,
reliability 255/255, txload 249/255, rxload 120/255
Encapsulation HDLC, crc 16, Data non-inverted
Keepalive set (10 sec)
Last input 00:00:01, output 00:00:00, output hang never
Last clearing of "show interface" counters 4w1d
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 915277
Queueing strategy: weighted fair
Output queue: 41/1000/64/915277 (size/max total/threshold/drops)
Conversations 11/19/64 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 192 kilobits/sec
5 minute input rate 121000 bits/sec, 42 packets/sec
5 minute output rate 250000 bits/sec, 42 packets/sec
41316538 packets input, 1297929738 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
3 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 3 abort
43061143 packets output, 1165133767 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
no alarm present
Timeslot(s) Used:5-8, subrate: 64Kb/s, transmit delay is 0 flags

#ping 1.2.3.2 repeat 100
Type escape sequence to abort.
Sending 100, 100-byte ICMP Echos to 1.2.3.2, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100/100), round-trip min/avg/max = 56/370/1556 ms