Determining N etwork Application Requirements

If possible, try to obtain information on new network applications that will be deployed in your network. Try to find out what their network use requirements will be, how many computers will use the new applications, where they are located, and whether there are any bandwidth or link quality requirements. If you cannot increase the amount of bandwidth on your network, you may still be able to increase network performance by the use of Cisco IOS Software QoS features, inclu ding the followingi

• Simple queuing and traffic prioritization

• Adva nced switching methods

• Compressiof

• Cong estion avoidance

• Advanced queuing and co ng ^saion maEagement

• Toaffic shaping

• Applying ATM QoS

• Classifying traffic to provide QoS at various network points

The pattle to learn and unbierstaud t he effehts of how ap^icatb ns and technobgie s will always drive the need foo network quality enlaancements. Fow instanne, you may find that bra nch routers with smpIler WAN links require compressi on to sup port thh network applications that have been or are going to be deployed. After determining that the router will require the applications of compression techniques, you may find that the compression algorithm is very demanding on thn router's processor or memory. After you have decided to move forward with the plan to implement compression, you may have to increase the amount of memory or, in some cases, replace older equipment to support other technologies.

To check the processor use and process CPU allocation, use the show processes cpu command, as shown in Example 4-2.

Example 4-2. show processes cpu Command

Router#show

processes cpu

CPU utilization for

five seconds:

1%/C

one

minute

: 0%;

five minutes: 0%

PID Runtime(ms)

Invoked

uSecs

5Sec

1Min

5Min

TTY

Process

1

4

1650

2

0 .

00%

0

00%

0.

00%

0

Load Meter

2

1573

2653

592

1.

31%

0

49%

0.

34%

0

Exec

3

5701

990

5758

0 .

00%

0

04%

0.

05%

0

Check heaps

4

0

1

0

0 .

00%

0

00%

0.

00%

0

Pool Manager

5

0

2

0

0 .

00%

0

00%

0.

00%

0

Timers

6

4

61

65

0 .

00%

0

00%

0.

00%

0

Serial Backgroun

7

0

276

0

0 .

00%

0

. 00%

0.

00%

0

Environmental mo

8

0

143

0

0 .

00%

0

00%

0.

00%

0

ARP Input

9

5

6

833

0 .

00%

0

00%

0.

00%

0

DDR Timers

10

0

2

0

0 .

00%

0

. 00%

0.

00%

0

Dialer event

11

8

2

4000

0 .

00%

0

. 00%

0.

00%

0

Entity MIB API

12

0

1

0

0 .

00%

0

t00%

0.

00%

0

SERIAL A'detect

13

0

1

0

0 .

00%

0

00%

0.

. 00%

0

Critical Bkgnd

14

52

992

52

0 .

00%

0

00%

0.

00%

0

Net Background

15

4

59

67

0 .

00%

0

00%

0.

00%

0

Logger

16

48

8228

5

0 .

00%

0

00%

0.

00%

0

TTY Background

17

8

8380

0

0 .

00%

0

. 00%

0.

. 00%

0

Per-Second Jobs

18

16

8312

1

0 .

00%

0

00%

0.

. 00%

0

Partition Check

19

88

725

121

0 .

00%

0

00%

0.

00%

0

Net Input

20

12

1651

7

0 .

00%

0

00%

0.

00%

0

Compute load avg

21

3915

141

27765

0 .

00%

0

05%

0.

00%

0

Per-minute Jobs

The first line is often the most important part of the show processes cpu command: CPU utilization for five seconds: 1%/0%; one minute: 0%; five minutes: 0%. This one line displays the TPU utilization in 5-second, 1-minute, and 5-minute increments. This data can be displayed locally on the router by repeatedly issuing the command for immediate use, or you can use data collection software to collect data over a period of time and use it to find network trends, and determine future network requirements. The router shown in the preceding example is running at 0-percent utilization. If you notice a router that constantly runs at or more than 75-percent utilization, you may have to consider a router upgrade, or, in the case of the previous compression example, you may consider upgrading the smaller WAN circuit and disabling compression.

To g ather performance trend information from a router, the output of the show processes cpu command is m ost valuable when gatheaed over a period of time, including peak- and low-traffic times. If processor utilization is high, log the process IDs from the PID column that are consuming The most time. You might be able to disable some processes to save resources.

While gathermg processor utilization, you can gather memory utilization as well. Although sometimes difficult to read or understand, the show memory commands display quite a bit of information about the system utilization. There are many variations of the show memory command, one of the most useful of which is the show memory dead command.

As shown in Example 4-3, the show memory dead command displays a summary of the memory use, total, used, and free memory statistics, and then goes on to display all the dead nronesfes that sti!l have m em ohy alloca ted for tRe w use. Iuthis number Is large, you may need to Pind the dead process and work wirh the Tisco TAT and fix the problem.

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