Types and Configuration of VLAN in V-SOL PON Network

VLAN is a technology used to implement virtual workgroups and limit broadcast domains. It is widely used on Layer 2 switching networks. VSOL PON access devices work at the second layer of the TCP/IP model. They achieve the access and isolation of a large number of users and the access, isolation, and forwarding of multiple types of services via VLAN. The VLANs running on VSOL PON devices are different from traditional VLANs.

Access devices have a large number of users and provide multiple services such as HSI and VolP. To enable the access devices to differentiate between different user services when they process user packets, service flows are defined at the access node.

Part I. What is VLAN?

The communication mode in the V-SOL access network VLAN is the same as that in the traditional VLAN. Packets are forwarded by querying the MAC address table.

If a port is not found in the MAC address table, a packet on the port will be considered an unknown unicast and broadcast to all ports in the VLAN. If the mac and port are found in the VLAN, the packet will be forwarded.

Part II. Types and Configuration of VLAN in V-SOL PON Network

VSOL access network VLANs are the extended applications of traditional VLANs on common broadband access devices. Below are the types of VLAN in the V-SOL?PON?system.

1. There are 4 types of VLANs on ONU, including?Tag, Trunk, Translation, and Transparent.

Tag

The?ONU?VLAN type "Tag" is not the same as the traditional packet with VLAN ID tag. It's the same as the VLAN access mode mentions in previous lessons.

The following describes how the ONU GE port with "Tag" mode processes packets.

●?When untag packet comes from the PC, ONU will default add a tag of the VLAN ID to the packet and forward it to OLT.

●?When the packet with the same VLAN Tag comes from OLT, ONU will remove the VLAN Tag of the packet and forward it to the PC.

Trunk

The ONU VLAN type "Trunk" is the same meaning as the traditional packet with multi VLAN ID tag. The following describes how to process packets.

●?When untag packet comes from the PC, the switch will default add a tag of the VLAN ID to the packet and forward it to ONU. When ONU receives the packet from the switch, and the VLAN tag in the ONU GE port Trunk VLAN list, ONU will permit and forward the packet to OLT.

●?When the packet with the VLAN tag comes from OLT and the VLAN tag in the ONU GE port Trunk VLAN list, ONU will permit and forward the packet to switch. When switch receives the packet coming from ONU with the VLAN tag, then remove the VLAN tag and forward it to the PC.

Transparent

The ONU VLAN type Transparent is the extended application of traditional VLANs. Here will introduce how to process packets.

●?When untag packet comes from the PC, ONU will permit and forward the packet to OLT without VLAN ID.

●?When untag packet comes from OLT, ONU will permit and forward the packet to the PC without VLAN ID.

●?When packet with the VLAN tags comes from the switch, ONU will permit and forward the packet to OLT with VLAN IDs.

●?When packet with the VLAN tags comes from OLT, ONU will permit and forward the packet to switch with VLAN IDs.

Translation

The ONU VLAN type Translation is the extended application of traditional VLANs. Let's see how to process packets.

●?When ONU received the packet from the switch, and the VLAN tag in the ONU GE port Translation VLAN list (old VLAN), ONU will translate it to the new VLAN and forward the packet to OLT.

●?When the packet with the VLAN tag comes from OLT, and the VLAN tag matches in the ONU GE port Translation VLAN list (new VLAN), ONU will translate to the old VLAN and forward the packet to the switch.

2. There are 3 types of VLANs on OLT, which is the same as traditional VLANs including?Access, Trunk, and Hybrid. Besides, there are 2 extended attributes involving?Translation and QinQ.

OLT?default all PON port and Uplink port in the Hybrid mode, and all PVID is 1.

PON system there are 2 extended attributes(QinQ and Translation) on OLT.

Translation

In some network environments, the OLT belongs to a private owner. The VLAN design will conflict with the service provider. So will use this VLAN translation to avoid that.

●?When the packet with the VLAN tag comes from ONU and the VLAN tag match in the OLT PON port Translation VLAN list (Customer VLAN), OLT will translate to Service VLAN and forward the packet to Carrier Network.

●?When the packet with the VLAN tag comes from Carrier Network and the VLAN tag match in the OLT PON port Translation VLAN list(Services VLAN), OLT will translate to Customer VLAN and forward the packet to ONU.

QinQ

A QinQ VLAN applies to a scenario when multiple ISPs use the same OLT to serve different users. The OLT forwards packets to different carriers according to the outer VLAN tag of the packets. Besides, the ISPs differentiate users and provide different services based on the inner VLAN tag of the packets.

Packets with two VLAN tags traverse the backbone network of a service provider and reach the BRAS for authentication based on double VLAN tags.

User 1 sends an untagged packet to the ONU and ONU will add Cvlan 100 to OLT. When OLT receives packet with VLAN ID 100, the OLT adds Svlan 10(Cvlan 100 and Svlan 10) to ISP1.

ISP 1 sends double VLAN tags(Cvlan 100 and Svlan 10) packet to OLT. OLT remove Svlan 10 and send to ONU. When ONU receives the packet with VLAN ID 100, the ONU remove the Cvlan 100 to User 1.

Source: https://www.vsolcn.com/blogs-detail/types-and-configuration-of-vlan