The network users at the London site consider e-mail, calendar access, and file transfer to be the most important uses of the network. The actual usage pattern is shown in Figure 3-12.
To design the class hierarchy and assign the bandwidth and priority to the classes for the London site, it is necessary to consider the following:
The data on actual network use
Information about user preferences
The patterns in the traffic originating in Paris and Bonn, according to their own bandwidth management configurations
The difference in capacity of the links connecting Paris and Bonn to London (the Bonn to London link has three times the capacity of the Paris to London link).
Taking all this into account, the network administrator decided to run the Solaris Bandwidth Manager software on the host that runs the routing software, and designed the class hierarchy shown in Figure 3-13.
The classes shown in parentheses are not actual classes, but remind the network administrator to allow bandwidth in a parent class where the child classes do not account for all the traffic. In the http class, for example, there are two child classes, for traffic to the US and to Europe. There will also be http traffic that is not going to the US or Europe. This traffic will be allocated to the http class, so the percentage of bandwidth allocated to the http class should not all be shared between the child classes. Table 3-3 shows the percentage of bandwidth and the priority assigned to each class.
Class Description |
Class Name |
Parent Class |
Percentage of Bandwidth Allocated |
Priority |
---|---|---|---|---|
Root |
root |
|
100 |
1 |
http |
http |
root |
35 |
4 |
http to US |
http-to-US |
http |
20 |
2 |
http to US from Paris |
http-Paris-to-US |
http-to-US |
4 |
4 |
http to US from Bonn |
http-Bonn-to-US |
http-to-US |
10 |
2 |
http to US from UK |
http-UK-to-US |
http-to-US |
4 |
4 |
http to Europe |
http-to-europe |
http |
10 |
4 |
Electronic mail |
|
root |
30 |
3 |
e-mail from Paris |
email-paris |
|
5 |
3 |
e-mail from Paris (IMAP) |
email-paris-imap |
email-paris |
4 |
3 |
e-mail from Paris (SMTP) |
email-paris-smtp |
email-paris |
1 |
6 |
e-mail from Bonn |
email-bonn |
|
15 |
3 |
e-mail from Bonn (IMAP) |
email-bonn-imap |
email-bonn |
12 |
3 |
e-mail from Bonn (SMTP) |
email-bonn-smtp |
email-bonn |
3 |
5 |
e-mail using IMAP |
email-imap |
|
7 |
3 |
e-mail using SMTP |
email-smtp |
|
2 |
5 |
FTP |
ftp |
root |
15 |
7 |
System administration |
sysadmin |
root |
10 |
2 |
Telnet |
telnet |
sysadmin |
5 |
1 |
System monitoring |
snmp |
sysadmin |
2 |
2 |
From system admin console |
administrator |
sysadmin |
2 |
1 |
Default |
default |
root |
5 |
7 |
The percentage of bandwidth allocated to a class containing traffic originating in Paris or Bonn takes into account the differences in the link capacity between those sites and the London site. For example, the classes for e-mail from Bonn have three times the allocation of the classes for e-mail from Paris.