Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
1. It detects Router Advertisements (and so, the respective ARs). The IPv6 addresses of these ARs,
the corresponding subnet prefixes, and the signal levels associated with the frames that contain
the respective Router Advertisements, are sent to the MTNM in a WLAN_INFO message. If no
Router Advertisements are received from the AR the MT is using, the IPv6 address of this AR
must nevertheless be included in the WLAN_INFO message with signal level “0” (this indicates
to the MTNM that the WLAN connection is lost).
2. The Router Advertisements received from the AR the MT is using, are sent to the IPv6 stack.
Any other Router Advertisements are not sent to the IPv6 stack. The filtering function knows the
AR the MT is using because, each time a handover is executed, the MTNM sends a message
USE_WLAN_AR to the WLAN driver. This message includes the IPv6 address of the AR to
use, and the respective network prefix.
3. All broadcast traffic that does not belong to the IPv6 subnet of the AR the MT is using, is
discarded. The subnet is identified by the source address of the packet, using the subnet prefix of
the subnet of the current AR.
4.2 Access Router Software Specification
Figure 29 depicts a functional overview of the Access Router (protocol communications with MT are not
shown in this figure).
The basic functional blocks are:
• The Fast Handover Module which is responsible for an appropriate context transfer for intra-mobility
scenarios.
• A Paging Attendant which is responsible for paging in the connected access cell.
• The AAAC Framework which is represented by a Metering module and the AAAC Attendant.
• A QoS Attendant which is responsible for executing QoS related actions on the Access Router.
• The Enhanced IPv6 stack and the Network Device Drivers.
• The Logger which is responsible for logging availability, registration, and authorization events.
All these modules will be described in greater detail in the following sections.
4.2.1 Overview of the different components
This section splits the components identified before in sub-blocks, giving an overview of their role. The
detailed behaviour of these sub-blocks and their interactions will be detailed in the next chapter.
4.2.1.1 Fast Handover Module / MIPL
It provides the implementation of fast handover procedures. Also, this module will take care of the
context transfer of some AAAC, and security parameters that will be done between the old AR and the
new AR to speed up handover. QoS context is transferred by the QoS infrastructure.
4.2.1.2 Paging Attendant
The IP paging attendant implements procedures for IP paging support:
1. Procedures for PA discovery.
2. Procedures for paging request. PA will send paging requests from which the AR will create an
on-link paging request to awake the dormant MT (if it is in the corresponding cell).
4.2.1.3 Network Device Driver /WLAN
This is a standard WLAN driver. In Moby Dick the hostap driver (http://hostap.epitest.fi/), version 19-05,
by Jouni Malinen is used.
4.2.1.4 Enhanced IPV6/IPSec/DiffServ packet Filter
The enhanced IPv6 stack is based on the IPv6 stack of the linux kernel 2.4.16. Functionality that must be
present:
• Standard IPv6 functionality.
• IPSec: for authentication of packets.
• Mobile-Ipv6, needed for Fast-Handoff implementation
• Diffserv and packet filter, that includes:
o Filtering: all packets received must belong to a flow in the DSCP table or they must be
signalling packets for network access procedures (a particular DSCP code) that must be
given to upper layers. If not, they must be dropped.
o Shaping: when sending packets, to control that flows adjust to agreed bandwidth.
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