I am working on QOS hands-on practice on my workbook from wanted to share this
and I would be very happy if someone found something wrong with this
configuratoin
or if this is helpfull to some of you.
I got through the QOS maps on the switches by the "Dirty trick" of
creating a auto-qos for ip-phone on a switchport. So I got the commands
that I could copy and work from. The excersise was instructing not to use
auto-qos
but this way you can copy the output that auto-qos does (which is quite messy)
and put it into notepad. Reload the switch and use what you need. That way
you don´t have to memorize cos-to-dscp mappings and so on. But I noticed
that auto-qos puts some commands and service policy straight on the interface
which is probably not what I want.
What about you QOS experts. Do you agree with this method. Do you think
they will give instruction in the exam to not use auto-qos and this would
be the the easy way out ?
Anyways the next excersise was to configure policies on a CME router's
and put them on a loopback interface.
There were basically 2 kinds of setups they want me to practice.
use NBAR auto discovery for auto recognition and mark packets and so on.
The question is like this:
"Configure a loopback interface on the CME router (IP address 10.10.99.254/24)
Configure the router so that voice traffic sent out of this interface is
affected
a DSCP value of EF. Use NBAR to identify Voice traffic:
Then do add they asked me to add signaling traffic to the schenario. So it would
receive AF31 and still use NBAR to identify SCCP and SIP signaling (voice
controll)
These 2 configuration excersice looks like this after completing:
!
class-map match-all voice
match protocol rtp audio
class-map match-any signaling
match protocol skinny
match protocol sip
match protocol h323
!
!
policy-map voip
class voice
set dscp ef
policy-map voip2
class voice
set dscp ef
class signaling
set dscp af31
!
interface Loopback0
ip address 10.99.99.254 255.255.255.0
ip nbar protocol-discovery
service-policy input voip2
service-policy output voip
!
now it gets more tricky for the next question:
"Change your QOS policy so that voice traffic is sent out of the loopback
interface is affected a DSCP value of EF. Voice controll must reveive AF31.
Your network uses sccp/skinny (tcp 2000) and h323 (udp 1720). Use ports to
identify the different traffic types"
I am preety sure that this last line implies that i remove NBAR even though I
could use it. I like this method where they let you change configurations that
you already did cause it makes you understand what is asked for and certain
small details in the question is more clear this way.
So my configuration after this one looks like this:
I just keep all the config in there. Hope nobody gets confused :-)
!
access-list 101 permit udp any any range 16384 32767
access-list 102 permit tcp any any eq 2000
access-list 102 permit udp any any eq 1720
!
class-map match-all voice_ports
match access-group 101
class-map match-all signaling_ports
match access-group 102
class-map match-all voice
match protocol rtp audio
class-map match-any signaling
match protocol skinny
match protocol sip
match protocol h323
!
!
policy-map voip
class voice
set dscp ef
policy-map voip2
class voice
set dscp ef
class signaling
set dscp af31
policy-map voip3
class voice_ports
set dscp ef
class signaling_ports
set dscp af31
!
interface Loopback0
ip address 10.99.99.254 255.255.255.0
service-policy input voip2
service-policy output voip3
!
One tip at the end:
to see if NBAR was working. I just opened up my Cisco softphone (IP
communicator) and routed my Callmanagers
ip to the loopback interface. Then I have this show commands to see if there
are hits by NBAR. Any more good QOS
verification commands that you guys can share ?
!
CME-practice-home-router#show ip nbar protocol-discovery protocol skinny
Loopback0
Last clearing of "show ip nbar protocol-discovery" counters 01:05:41
Input Output
----- ------
Protocol Packet Count Packet Count
Byte Count Byte Count
5min Bit Rate (bps) 5min Bit Rate (bps)
5min Max Bit Rate (bps) 5min Max Bit Rate (bps)
------------------------ ------------------------ ------------------------
skinny 0 32
0 15264
0 0
0 3000
unknown 0 12
0 608
0 0
0 0
Total 0 62
0 16592
0 0
0 3000
!
regards. Kristjan
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