Network administrators evaluate an application’s performance by measuring response time, round trip time, packet loss, and delay. However, this method poses certain limitations because you can monitor only the applications, servers, and network devices within the hosted network boundary. And, if the applications are hosted in the cloud, monitoring is almost impossible.
When users complain of delayed response from applications hosted in the cloud, the actual delay could be due to the application, client network, server network, transaction, or response time. Therefore, tracking the actual reason could be a cumbersome, time-consuming, and tedious. In such scenarios, the network admin needs a powerful tool like Cisco Application Visibility and Control (AVC) that helps analyze these metrics in a jiffy!
Implementing AVC
AVC combines several technologies to help network admins quickly analyze and narrow down the bottlenecks. One of the technologies that AVC uses is application response time (ART).
Using ART, you can gauge the performance of thousands of applications on the network. The following scenario helps explain how this works. Company A has subscribed to various cloud services and primarily uses WebEx to host online web sessions, TelePresence for video conference, and Dropbox for online storage.
Let’s say there is a drop in the performance of WebEx and Telepresence. The company already runs on Cisco technology with the Cisco ISR g2 platform as its WAN router, the network administrator configures Cisco AVC ART on the Cisco ISR platform as follows:
flow exporter NFA
destination 172.18.158.71
source GigabitEthernet0/0
output-features
transport udp 9996
export-protocol netflow-v9
template data timeout 60
option interface-table
option application-table
option application-attributes
option metadata-version-table
!
!
class-map match any NFA_ART
match any
!
!
flow record type mace NFA
collect ipv4 dscp
collect interface input
collect interface output
collect application name
collect counter client bytes
collect counter server bytes
collect counter client packets
collect counter server packets
collect art all
!
!
flow record type performance-monitor NFA_NBAR
match ipv4 tos
match ipv4 protocol
match ipv4 source address
match ipv4 destination address
match transport source-port
match transport destination-port
match interface input
match interface output
match flow direction
match application name
collect datalink dot1q vlan input
collect datalink dot1q vlan output
collect routing destination as
collect routing next-hop address ipv4
collect ipv4 dscp
collect ipv4 id
collect ipv4 source prefix
collect ipv4 source mask
collect ipv4 destination mask
collect transport tcp source-port
collect transport tcp destination-port
collect transport tcp flags
collect transport udp source-port
collect transport udp destination-port
collect counter bytes
collect counter packets
collect timestamp sys-uptime first
collect timestamp sys-uptime last
!
!
flow monitor type performance-monitor NFA
record NFA_NBAR
exporter NFA
cache timeout synchronized 60
!
!
flow monitor type mace NFA-ART
record NFA
exporter NFA
!
!
policy-map type performance-monitor NFA
class class-default
flow monitor NFA
!
!
policy-map type mace mace_global
class NFA_ART
flow monitor NFA_ART
Applying the monitor to interface and enabling MACE on the interface to collect ART metrics
interface GigabitEthernet0/0
ip address x.x.x.x
service-policy type performance-monitor input NFA
service-policy type performance-monitor output NFA
mace enable
Interpreting ART
To interpret ART metrics, the easiest option is to parse them using a NetFlow analysis tool such as Netflow Analyzer from ManageEngine. NetFlow Analyzer brings with it easy-to-use bandwidth monitoring software. In addition, NetFlow Analyzer supports Cisco AVC and can be deployed anywhere on the network to collect metrics and generate reports. Here are some of the ART reports that NetFlow Analyzer generates:
Using these reports, a network admin can easily narrow down the problem. If the problem is on the client network, the admin might reinforce some strong QoS policies on the edge router to prioritize business-critical application traffic. And, if the delay is due to the application or server network, the cloud service provider may have to tweak the service.
Watch this space for more on application performance analysis. In the next blog, we’ll discuss the benefits of another technology that’s part of Cisco AVC.
Supported IOS
Cisco ASR 1000 platform: IOS XE 3.4S or above
Cisco ISR G2 : IOS Release 15M&T
You can download NetFlow Analyzer version which supports Cisco AVC from here.
Interested in evaluating the Cisco AVC reporting available in NetFlow Analyzer. Get in touch with NetFlow Analyzer TAC by sending an email to nfs@manageengine.com.
References
http://www.cisco.com/en/US/prod/collateral/routers/ps9343/qa_c67-695977.html
http://www.cisco.com/en/US/prod/routers/avc_control.html#~overview
http://www.cisco.com/en/US/solutions/collateral/ns1015/ns483/ns780/at_a_glance_c45-649117.pdf
