Amer Networks SS2R48G4i V2 - Manual (Page 102)

SS2R24G4i/SS2R48G4i
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metropolitan area network using layer-3 switch as backbone equipment.
As shown in Fig 5-4, after being enabled on the user port, dot1q-tunnel assigns each user an
SPVLAN identification (SPVID). Here the identification of user is 3. Same SPVID should be assigned
for the same network user on different PEs. When packet reaches PE1 from CE1, it carries the VLAN
tag 200-300 of the user internal network. Since the dot1q-tunnel function is enabled, the user port on
PE1 will add on the packet another VLAN tag, of which the ID is the SPVID assigned to the user.
Afterwards, the packet will only be transmitted in VLAN3 when traveling in the ISP internet network
while carrying two VLAN tags (the inner tag is added when entering PE1, and the outer is SPVID),
whereas the VLAN information of the user network is open to the provider network. When the packet
reaches PE2 and before being forwarded to CE2 from the client port on PE2, the outer VLAN tag is
removed, then the packet CE2 receives is absolutely identical to the one sent by CE1. For the user, the
role the operator network plays between PE1 and PE2,is to provide a reliable layer-2 link.
The technology of Dot1q-tuunel provides the ISP internet the ability of supporting many client
VLANs by only one VLAN of theirselves. Both the ISP internet and the clients can configure their own
VLAN independently.
It is obvious that, the dot1q-tunnel function has got following characteristics
z Applicable through simple static configuration, no complex configuration or maintenance
to be needed.
z Operators will only have to assign one SPVID for each user, which increases the number
of concurrent supportable users; while the users has got the ultimate freedom in selecting
and managing the VLAN IDs (select within 1~4096 at users’ will).
z The user network is considerably independent. When the ISP internet is upgrading their
network, the user networks do not have to change their original configuration.
Detailed description on the application and configuration of dot1q-tunnel of SS2R24/48G4i switch
will be provided in this section
9.3.2 Configuration Task Sequence Of Dot1q-Tunnel
1. Configure the dot1q-tunnel function on the ports
2. Configure the type of protocol (TPID) on the ports
3. Configure the dot1q-tunnel type of the port.
1.Configure the dot1q-tunnel function on the ports
Command Explanation
Port mode
dot1q-tunnel enable
no dot1q-tunnel enable
Enter/exit the dot1q-tunnel mode on
the ports.