Thursday, February 22, 2007
Ok, now we come to part 2 in the Voice QoS, in the first part we concluded when (I hope) we understand that Voice and QoS need to go together in order to
Achieve a good and working env that will allow us to use all our application wisely.
Also I have mentioned the wonderful NBAR, let me tell you this is the nicest tool I used in a long time and I am not kidding, what is better then simply
Entering under the interface you want to see what is going on
!
Interface X
ip nbar protocol-discovery
!
and poof like magic all your traffic is colored not pain no hassle you can see a table like so:
sh ip nbar protocol-discovery stats bit-rate top-n 10
FastEthernet0/0
Input Output
Protocol 5 minute bit rate (bps) 5 minute bit rate (bps)
------------------------ ------------------------ ------------------------
http 15000 13000
ssh 2000 0
rtp 21000 20000
smtp 0 0
secure-http 0 0
rtspplayer 0 0
eigrp 1000 0
icmp 0 0
pop3 2000 1000
dns 0 0
unknown 1000 1000
Total 42000 35000
Tell me isn’t it nice, now I can see clearly all my traffic marked and I can do what ever I want with it.
Today networks are hybrid use all in one voice data video and as such each network need to be carefully examine and based on examination preparing
a base line configuration for QoS.
I have set on one of my network a classification like so:
class-map match-any VOIP
match protocol rtp audio
class-map match-any DATA
match protocol http
match protocol ftp
match protocol tftp
match protocol secure-http
match protocol secure-ftp
match protocol pop3
match protocol smtp
match protocol secure-pop3
match protocol snmp
class-map match-any P2P
match protocol gnutella
match protocol gopher
match protocol novadigm
match protocol kazaa2
match protocol fasttrack
match protocol napster
class-map match-any HTTP_ATTACK
match protocol http url "*.ida*"
match protocol http url "*cmd.exe*"
match protocol http url "*root.exe*"
match protocol http url "*readme.eml*"
classifying the most used and unwanted traffic!
policy-map OFFICE
class VOIP
priority 100
set dscp ef
class P2P
drop
class DATA
bandwidth percent 40
policy-map OFFICE_IN
class HTTP_ATTACK
drop
implementing a policy like so based on ~3 simultaneous voice calls setting for them a DSCP tag ef and any P2P I simply dropping where to Data
I give at lease 40% of bandwidth
on the incoming direction traffic matching the HTTP_ATTACK class I drop it also giving me some security using NBAR.
So Now I showed you how you can use it on your Cisco nicely with a real world sample but be advised what is good for my network is not always and
most cases isn’t what is good for yours so I strongly advice you start getting familiar first with nbar and what it can give you, then prepare you own network
Baseline and then implement you own policy.
Good Luck
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment