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Static IP Access method
The DSLAM supports bridged encapsulation at U interface defined by DSL Forum in WT-101
(Migration to Ethernet Based DSL Aggregation, Rev.7, May. 2005) on Figure 4 stack a.
DSLAM supports filtering options in order to prevent L2 traffic between DSL customers connected
to the same DSLAM considering Static IP environment (Intra-DSLAM filtering).
DSLAM supports filtering options in order to prevent L2 traffic between DSL customers connected
to different DSLAMs considering Static IP environment (Inter-DSLAM filtering) considering N:1
VLAN forwarding.
Intra-DSLAM and Inter-DSLAM filters of the DSLAM are capable to be disabled partly or entirely
on VLAN basis.
DSLAM provides positive Ethertype filtering with the following Ethertype values in upstream
direction
‧ 0x0800: IP
‧ 0x0806: ARP
Positive filtering means, that DSLAM transmits Ethernet frames only with the defined Intertype
values.
IVD can filter Ethernet Broadcast frames in downstream direction.
IVD provides capabilities to prevent BRAS (Gateway) MAC spoofing.
IVD supports proxy ARP function.
IVD transmits traffic only originates from given source IP address(es).
Transparent LAN Service (L2VPN)
The IVD solution provides additional requirements in order to support L2 VPN service
(Transparent LAN).
The system is the possibility of totally transparent L2 transport of L2 VPN service
Ethernet frames, including
‧ unicast, multicast and broadcast frames,
‧ tagged and untagged frames and
‧ frames with special content (e.g. L2 Control Protocol, Routing).
The transparent L2 transport results in L3 independence, so customers can use whatever L3
protocols (e.g. IP, IPX, etc.).
There are two scenarios when a L2-VPN is implemented over Ethernet transport:
‧ Routers (L3 CPE) at ADSL endpoints
‧ Switches (L2 CPE) at ADSL endpoints
The IVD can support both of the L2VPN solutions.
Routers (L3 CPE) at ADSL endpoints
The DSLAM transparent for unicast, multicast and broadcast traffic originates from subscriber.
Dynamic routing protocol exchange routing information using MC frames which addresses are in
the Local Network Control Block (224.0.0/24) and in some cases in the Internetwork Control Block
(224.0.1/24). Some examples are as follows: RIPv2 (224.0.0.9), OSPF (224.0.0.5, 224.0.0.6),
(E)IGRP (224.0.0.10), PIMv2 (224.0.0.13, 224.0.1.39, 224.0.1.40), etc.
The DSLAM is transparent for dynamic routing protocols which use multicast MAC/IP addresses.
The DSLAM supports bridged encapsulation at U interface defined by DSL Forum in WT-101
(Migration to Ethernet Based DSL Aggregation, Rev.7, May. 2005) on Figure 4 stack a.
The DSLAM supports routed encapsulation at U interface defined by DSL Forum in WT-101
(Migration to Ethernet Based DSL Aggregation, Rev.7, May. 2005) on Figure 4 stack c.
In case of routed encapsulation DSLAM is able to convert routed to bridged encapsulation
DSLAM provides N:1 forwarding for VLAN allocation.
Considering bridged encapsulation and N:1 scenario. The DSLAM provides possibility to limit the
MAC addresses originates from the DSL endpoints in order to protect the MAC table of the
devices.
DSLAM is able to add 802.1ad tag in upstream direction.
DSLAM is able to remove 802.1ad tag in downstream direction.
At the uplink interface of the DSLAM will use a unique virtual MAC address per PVC as source
address in case of routed encapsulation of RFC2684.
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Version: 1.5
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