Installation

Before You Install the Software

Shortcut Method Assuming B = P for all VCs, TM can be rounded to:

If B < 512, TM = approx. (1,536 + (2 x W + 2) x B) x No. of VCs

If B > or = 512, TM = approx. (2 x W + 5) x B x No. of VCs The following table (in bytes/VC) provides a quick guide:

Table 2-1

 

 

 

Buffer Size (B) = Packet Size (P) in bytes

 

 

 

 

 

 

 

 

 

 

 

 

 

128

256

512

1024

2048

4096

 

 

 

 

 

 

 

 

 

 

Window (W)

1

2 K

2.5 K

3.5 K

7 K

14 K

28 K

 

size

 

 

 

 

 

 

 

 

2

2.3 K

3 K

4.5 K

9 K

18 K

36 K

 

 

 

 

 

 

 

 

 

 

 

 

 

3

2.5 K

3.5 K

5.5 K

11 K

22 K

44 K

 

 

 

 

 

 

 

 

 

 

 

4

2.8 K

4 K

6.5 K

13 K

26 K

52 K

 

 

 

 

 

 

 

 

 

 

 

5

3 K

4.5 K

7.5 K

15 K

30 K

60 K

 

 

 

 

 

 

 

 

 

 

 

6

3.3 K

5 K

8.5 K

17 K

34 K

68 K

 

 

 

 

 

 

 

 

 

 

 

7

3.5 K

5.5 K

9.5 K

19 K

38 K

76 K

 

 

 

 

 

 

 

 

 

Example 2-1Example:

 

 

 

 

 

 

A system has two X.25 cards configured as follows:

Card 1:

Window = 2 Packet size = 1024

Socket buffer size = 4096 (default) 200 VCs are used

Card 2:

Window = 4 Packet size = 128

Socket buffer size = 4096 (default) 400 VCs are used

26

Chapter 2