New to QOS - How is offered rate decided?

bret · ‎02-03-2012

I am working with QoS and came across what I feel is an inconsitency. The following configurations are in place from a QoS perspective. If I have a 50mb WAN link (which is correctly negotiating) why would my offered rate be so low? I feel that this is not allowing me to take full advantage of a 50mb link, but I could be wrong. Also, am I write to put backup traffic under af11? Any help&info, or links to reading material would be extremely helpful.

class-map match-all ds_af21

match access-group name qos_class2_traffic

class-map match-all ds_af31

match access-group name qos_class3_traffic

class-map match-all ds_af11

match access-group name qos_class1_traffic

policy-map ds_marker

class ds_af11

set ip dscp af11

class ds_af21

set ip dscp af21

class ds_af31

set ip dscp af31

ip access-list extended qos_class1_traffic

remark corporate_email_traffic

permit ip any host x.x.x.x

remark backup_traffic

permit ip any host x.x.x.x

ip access-list extended qos_class2_traffic

remark network_mgmt_traffic

permit ip any host x.x.x.x

ip access-list extended qos_class3_traffic

remark NMS_Traffic

permit ip any host x.x.x.x

int f0/1

service-policy output ds_marker

Class-map: ds_af11 (match-all)

4138885 packets, 4292097825 bytes

5 minute offered rate 13000 bps, drop rate 0 bps

Match: access-group name qos_class1_traffic

QoS Set

dscp af11

Packets marked 4138886

Class-map: ds_af21 (match-all)

291442 packets, 58068428 bytes

5 minute offered rate 1000 bps, drop rate 0 bps

Match: access-group name qos_class2_traffic

QoS Set

dscp af21

Packets marked 291442

Class-map: ds_af31 (match-all)

71839 packets, 6597765 bytes

5 minute offered rate 0 bps, drop rate 0 bps

Match: access-group name qos_class3_traffic

QoS Set

dscp af31

Packets marked 71839

Class-map: class-default (match-any)

62196411 packets, 31898803744 bytes

5 minute offered rate 196000 bps, drop rate 0 bps

Match: any

FastEthernet0/1 is up, line protocol is up

Hardware is Gt96k FE, address is 0013.7f92.2aa1 (bia 0013.7f92.2aa1)

Description:

Internet address is x.x.x.x/30

MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 100Mb/s, 100BaseTX/FX

Extended IP access list qos_class1_traffic

10 permit ip any host x.x.x.x (34690472 matches)

20 permit ip any host x.x.x.x (41904411 matches)

30 permit ip any host x.x.x.x (1144608 matches)

Extended IP access list qos_class2_traffic

10 permit ip any host x.x.x.x (35457 matches)

20 permit ip any host x.x.x.x (13462361 matches)

Extended IP access list qos_class3_traffic

30 permit ip any host x.x.x.x (40617 matches)

Thanks in advance!

Joseph W. Doherty · ‎02-04-2012

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Posting

I am working with QoS and came across what I feel is an inconsitency. The following configurations are in place from a QoS perspective.  If I have a 50mb WAN link (which is correctly negotiating) why would my offered rate be so low? I feel that this is not allowing me to take full advantage of a 50mb link, but I could be wrong. Also, am I write to put backup traffic under af11? Any help&info, or links to reading material would be extremely helpful.

There could be many reasons why your offered rate is so low. Much depends on the nature of what the hosts are attempting to do. It could be somewhere along the path there are a lot of errors or a bottleneck adverse to transfers. It could be WAN latency is slowing the effective rate.

AF11 is recommended for "bulk" traffic, so backup traffic might be marked as such, but if you also had large file transfers, you could mark them AF11 and perhaps use AF12 or AF13 for backups.

Regarding references, unfortunately there are so many, you need to be precise in what you're trying to learn. For example, you might search on AF11, QoS, "bulk"; you might also search on BDP (bandwidth delay product). Cisco has much good information, so you might first try searching just Cisco's site and then extend search to the rest of the Internet.

bret · ‎05-30-2012

Would something like this be suiting to marking with AF13 for backup traffic?

class-map match-all ds_af13

match access-group name qos_class4_traffic

policy-map ds_marker

class ds_af13

set ip dscp af13

ip access-list extended qos_class4_traffic

remark network backups

permit ip any host x.x.x.x