2.2.4.1. TOS Byte 
The TOS byte can be read in a number of different ways:
- Two 3-bit values for precedence and priority
- One 6-bit value as a combination of both 3-bit values (DiffServ CP)
- The entire TOS byte including two fill bits
For IPDA, the entire TOS byte is specified. The two least significant
bits are always set to zero. See also Section 1.1,
“Key Words”.
Table 3. TOS values
|
Type
|
Traffic type
|
HW
|
TOS byte
|
IEEE 802.1 p/q Priority
|
||||
|
Package Handling Behavior
How should packages of this traffic type be
handled?
|
With DiffServ
CodePoint
(default)
|
Without DiffServ
|
||||||
|
Binary
|
Dec
|
Binary
|
Dec
|
|||||
|
TOSPL
|
VoIP payload
|
HG 3500
HG 3575
|
1011 1000 (EF)
|
184
|
0001 0000
|
16
|
5
|
|
|
Minimal delay
Slight packet loss
|
||||||||
|
TOSSIGNL
|
Signaling between OpenScape 4000 and access
point
|
OpenScape 4000
|
0110 1000
(AF31)
|
104
|
0001 0100
|
20
|
3
|
|
|
Minimal packet loss
Slight delay
|
||||||||
|
TOSLAN
|
Signaling via LAN
|
AP
|
0110 1000
(AF31)
|
104
|
0001 0100
|
20
|
3
|
|
|
Minimal packet loss
Slight delay
|
||||||||
|
TOSMODEM
|
Signaling via Survivability connection
|
0111 0000
(AF 32)
|
112
|
0001 0000
|
16
|
-
N/A, as PPP connection
|
||
|
Minimal packet loss
Slight delay
|
||||||||
The values for TOSSIGNL (AMO CGWB, AMO SIPCO), TOSLAN
(AMO STMIB) and TOSMODEM may not be zero. TOSLAN and TOSMODEM
must be set differently to each other. TOSPL is set in AMO CGWB,
AMO SIPCO and AMO STMIB.
It is important that the required behavior (Package Handling Behavior)
is achieved in the network. The absolute numerical values for TOS and
IEEE 802.1 priority are not important in this case. They are used solely
for the purposes of identifying the required Package Handling Behavior.
The values mentioned in the table are the default settings of the
IP gateway loadware (STMI/NCUI). These settings fulfill the OSCAR specifications.
You can change the L2 priority with
The values for VLAN priority (layer 2) cannot be
changed via AMO. Therefore the L2 priority for the signaling connection
(CCA/CCB, AMO SIPCO) is hard coded.
IMPORTANT:
If you change the TOS values for HG 3500
with AMO CGWB you have to reboot the corresponding gateways with
AMO BSSU. If you change the TOS values for HG 3575 using AMO
STMIB you have to an
EXEC-USSU:UPDATAP; or a REST-USSU:LTU;
depending which parameter you changed. Both commands will generate a
restart of the shelf. If you want to change the values with AMO SIPCO
please do a soft restart for CCA and CCB.Value range of the TOS values (0-255)
As of HiPath 4000 V5 R1 the value range of the TOS values (0-255)
has been extended (see Table 4, “TOS byte correspondences”.
IMPORTANT:
The column “Decimal 8-Bit” contains the values
which are needed for the AMO commands. The other columns are only for
informational purposes.
Table 4. TOS byte correspondences
|
DSCP-value
|
Decimal 6-bit
|
Decimal 8-Bit
|
hexadecimal 6-Bit
|
hexadecimal 8-Bit
|
|
DSCP63
|
63
|
252
|
3F
|
FC
|
|
DSCP62
|
62
|
248
|
3E
|
F8
|
|
DSCP61
|
61
|
244
|
3D
|
F4
|
|
DSCP60
|
60
|
240
|
3C
|
F0
|
|
DSCP59
|
59
|
236
|
3B
|
EC
|
|
DSCP58
|
58
|
232
|
3A
|
E8
|
|
DSCP57
|
57
|
228
|
39
|
E4
|
|
CS7
|
56
|
224
|
38
|
E0
|
|
DSCP55
|
55
|
220
|
37
|
DC
|
|
DSCP54
|
54
|
216
|
36
|
D8
|
|
DSCP53
|
53
|
212
|
35
|
D4
|
|
DSCP52
|
52
|
208
|
34
|
D0
|
|
DSCP51
|
51
|
204
|
33
|
CC
|
|
DSCP50
|
50
|
200
|
32
|
C8
|
|
DSCP49
|
49
|
196
|
31
|
C4
|
|
CS6
|
48
|
192
|
30
|
C0
|
|
DSCP47
|
47
|
188
|
2F
|
BC
|
|
EF
|
46
|
184
|
2E
|
B8
|
|
DSCP45
|
45
|
180
|
2D
|
B4
|
|
DSCP44
|
44
|
176
|
2C
|
B0
|
|
DSCP43
|
43
|
172
|
2B
|
AC
|
|
DSCP42
|
42
|
168
|
2A
|
A8
|
|
DSCP41
|
41
|
164
|
29
|
A4
|
|
CS5
|
40
|
160
|
28
|
A0
|
|
DSCP39
|
39
|
156
|
27
|
9C
|
|
AF43
|
38
|
152
|
26
|
98
|
|
DSCP37
|
37
|
148
|
25
|
94
|
|
AF42
|
36
|
144
|
24
|
90
|
|
DSCP35
|
35
|
140
|
23
|
8C
|
|
AF41
|
34
|
136
|
22
|
88
|
|
DSCP33
|
33
|
132
|
21
|
84
|
|
CS4
|
32
|
128
|
20
|
80
|
|
DSCP31
|
31
|
124
|
1F
|
7C
|
|
AF33
|
30
|
120
|
1E
|
78
|
|
DSCP29
|
29
|
116
|
1D
|
74
|
|
AF32
|
28
|
112
|
1C
|
70
|
|
DSCP27
|
27
|
108
|
1B
|
6C
|
|
AF31
|
26
|
104
|
1A
|
68
|
|
DSCP2 5
|
25
|
100
|
19
|
64
|
|
CS3
|
24
|
96
|
18
|
60
|
|
DSCP23
|
23
|
92
|
17
|
5C
|
|
AF23
|
22
|
88
|
16
|
58
|
|
DSCP21
|
21
|
84
|
15
|
54
|
|
AF22
|
20
|
80
|
14
|
50
|
|
DSCP19
|
19
|
76
|
13
|
4C
|
|
AF21
|
18
|
72
|
12
|
48
|
|
DSCP17
|
17
|
68
|
11
|
44
|
|
CS2
|
16
|
64
|
10
|
40
|
|
DSCP15
|
15
|
60
|
F
|
3C
|
|
AF13
|
14
|
56
|
E
|
38
|
|
DSCP13
|
13
|
52
|
D
|
34
|
|
AF12
|
12
|
48
|
C
|
30
|
|
DSCP11
|
11
|
44
|
B
|
2C
|
|
AF11
|
10
|
40
|
A
|
28
|
|
DSCP9
|
9
|
36
|
9
|
24
|
|
CS1
|
8
|
32
|
8
|
20
|
|
DSCP7
|
7
|
28
|
7
|
1C
|
|
DSCP6
|
6
|
24
|
6
|
18
|
|
DSCP5
|
5
|
20
|
5
|
14
|
|
DSCP4
|
4
|
16
|
4
|
10
|
|
DSCP3
|
3
|
12
|
3
|
C
|
|
DSCP2
|
2
|
8
|
2
|
8
|
|
DSCP1
|
1
|
4
|
1
|
4
|
|
DF
|
0
|
0
|
0
|
0
|