Moby Dick Consolidated System Integration Plan
Moby Dick Consolidated System Integration Plan
Moby Dick Consolidated System Integration Plan
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D0103v1.doc Version 1 6.7.2003<br />
User<br />
AAAC<br />
Table update<br />
Module<br />
3b<br />
Filtering Rules & DSCP<br />
1 2 3a<br />
Service<br />
Table<br />
Character device<br />
/dev/ dscp<br />
1: Filters writing<br />
2: Filters reading<br />
DSCP<br />
Matching<br />
Table<br />
3a: DSCP update<br />
3b: Filters update<br />
Figure 51: DMT and SC update process<br />
For the moment, the table update process is triggered manually, by writing on the /dev/dscp character<br />
device. However, it is possible to make the AAAC system update the FD, in the same way than the DSCP<br />
update (see section 4.1.2.9.8) or triggering automatic updates regularly, in the user space.<br />
4.2.2.7.5 DSCP marking<br />
DSCP marking is done thanks to a modification of the Traffic Class and Flow Label fields in the IPv6<br />
header. When the information of the packet header matches with a filter, the corresponding DSCP is<br />
marked in the header of the packet: the four first bits of the DSCP are stored in the last four bits of the<br />
Traffic Class field, and the last two bits, plus two bits set to ‘0’, are stored in the four first bits of the Flow<br />
Label field.<br />
DSCP<br />
Vers<br />
TC<br />
…..<br />
Flow Label<br />
Figure 52: DSCP bits in the IPv6 main header<br />
4.2.2.7.6 Packet re-marking<br />
This operation is supported by the DMT, if the DMS is installed in a Linux router. To re-mark packets,<br />
the network administrator has just to add a new filter, containing a ‘IP6DSCP’ item, in the FD. This filter<br />
evaluates the DSCP in the new packet header, and associates a new value with it.<br />
4.2.3 Software implementation / interfaces<br />
4.2.3.1 Interface between QoSManager and Fast Handover module<br />
The Fast Handover modules, implemented in the Access Routers, handle fast handover related control<br />
messages. As specified in chapter 4 for the Fast Handover signalling flow, the oAR releases two further<br />
control messages on reception of the Router Solicitation for Proxy message. One message is related to the<br />
fast handover procedure and refers to the HI/HACK Fast-HO control message handshake between the<br />
oAR and the nAR. The second message that should be released is the QoS related control message<br />
initiating re-establishment of QoS context on the nAR and conveying QoS related information to the<br />
domains QoS brokers. This requires an appropriate local interface between the Fast-HO module and the<br />
QoS attendant function, which are both implemented on Access Routers.<br />
D0103v1.doc 64 / 168
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