Packet Walk-Throughs
9-3
8000-A2-GB21-20
November 1997
6. The 8540 DSL card then consults its routing table to identify the next hop to
forward the packet. Since a host route is defined for ES1 (route #2), the DSL
interface is used as the next hop.
7. The 8540 DSL card then forwards the packet over the DSL port to that RTU.
8. Upon receiving the packet, the RTU forwards the packet to its 10BaseT port.
Management Domain Packet Walk-Through
For an 8540 DSL card and its associated RTUs, all management functions are
performed by an agent on the DSL card.
Packet Walk-Through Using an 8546 DSL Card
Service Domain Packet Walk-Through
To examine how data packets flow through the service domain, an example of
ES1 issuing a ping to NSP1 will be used. The following assumptions are made:
A host route entry has been configured in the HotWire RTU for ES1
A source domain IP entry exists for the HotWire RTU
A static route exists between the 8546 DSL card and the HotWire RTU
Filtering is disabled
The following illustration shows how data packets flow through the service
domain. In this illustration ES1 is connected to the same LAN as the HotWire
RTU.
97-15474a
Router
155.1.2.1
155.1.3.1
NSP1
155.1.2.2
8546 DSL
Card
155.1.3.2
RTU
135.1.3.3
155.1.3.4
Unnumbered
DSL
Interface
ES1
Host/Net
1) 155.1.3.4
2) 155.1.3.4
Subnet Mask
255.255.255.255
255.255.255.255
Next-Hop Address
155.1.3.1
135.1.3.3
S/D (Source/Destination)
src (source)
dst (destination)
Partial DSL Routing Table
ES1 pings NSP1
NSP1 issues reply to ping
1
2
3
4
5
6
7
1
2
3 4
5
6
7
8
