Lucent Technologies 6000 User Manual

Page of 586
Defining Static Filters
Defining Type of Service filters
MAX 6000/3000 Network Configuration Guide
 15-21
Examples of defining a TOS filter 
The following examples define a TOS filter for TCP packets (protocol 6) that are destined for a 
single host at 10.168.6.24. The packets must be sent on TCP port 23. For incoming packets that 
match this filter, the priority is set at level 2. This relatively low priority, means that an 
upstream router that implements priority queuing may can these packets when it becomes 
loaded. The parameters also set TOS to prefer a low latency connection which means that the 
upstream router will choose a fast connection if one is available, even if it is higher cost, lower 
bandwidth, or less reliable than another available link.
srcport cmp 
value
If the 
srcport 
keyword is followed by a comparison symbol and 
a port, the port is compared to the source port of a packet. The 
comparison symbol can be < (less-than), = (equal), > (greater-than), 
or ! = (not-equal). The port value can be one of the following names 
or numbers: ftp-data (20), ftp (21), telnet (23), smtp (25), 
nameserver (42), domain (53), tftp (69), gopher (70), finger (79), 
www (80), kerberos (88), hostname (101), nntp (119), ntp (123), 
exec (512), login (513), cmd (514), or talk (517). For more details, 
see “Filtering by port numbers” on page 15-14.
precedence
 value
Specifies the priority level of the data stream. The three most 
significant bits of the TOS byte are priority bits used to set 
precedence for priority queuing. If a packet matches the filter, the 
bits are set to the specified value (most significant bit first). One of 
the following values can be specified:
000—Normal priority
001—Priority level 1
010—Priority level 2
011—Priority level 3
100—Priority level 4
101—Priority level 5
110—Priority level 6
111—Priority level 7 (the highest priority).
type-of-service
 
value
Type of Service of the data stream. If a packet matches the filter, the 
system sets the four bits following the three most significant bits of 
the TOS byte to the specified value. The four bits are used to 
choose a link according to the type of service. One of the following 
values can be specified:
Normal (0)—Normal service.
Disabled (1)—Disables TOS.
Cost (2)—Minimize monetary cost.
Reliability (4)—Maximize reliability.
Throughput (8)—Maximize throughput.
Latency (16)—Minimize delay.
Keyword or argument Description