VPLS (Virtual Private LAN Service) - Part 4 (VPLS versus h-VPLS) - www.ipcisco.com : www.ipcisco.com
Content Protection by DMCA.com

Comparison of VPLS and h-VPLS

VPLS (Virtual Private LAN Service) and h-VPLS (Hierarhical VPLS) has some common and different properties. So they have different aadvantages and disadvantages.In this article, we will focus on the comparison of these two concepts. The most important different between VPLS and h-VPLS is in the interface between the CE (Customer Edge) and the PE (Provider Edge). Until know, when we talk about Provider Edge devices of an MPLS network, we always use PE abbstraction. With the concept of h-VPLS, instead of one PE device, there are two PE device. u-PE (User facing Provider Edge) and n-PE (Network facing Provider Edge).

In VPLS (Virtual Private LAN Service), the CE devices are directly connected to the MPLS Core n-PE (Network facing Provider Edge) devices. In other words, CE device connects directly to an MPLS-enabled device. This device will be participate in routing (routing protocols) and label distribution (LDP).

In this type of VPLS, the Edge Device will perform many heavy facilities. For example it needs to hold routing tables, forwarding tables etc. It does many jobs as an only PE device. This is not an efficient solution for large scale networks.

Basic VPLS Architecture, Full Mesh

Basic VPLS Architecture, Full Mesh

In h-VPLS, the disadvantage of normal VPLS is bypassed with the usage of additional edge points . This point is called u-PE (User face of Provider Edge). The customer traffic is meet on the u-PE device. And this first point do not need to hold whole routing tables. It needs only the address of its peer n-PE device. This u-PE device can be a ethernet switch. And it transfers the different trunk traffic to the n-PE device. u-PE device uses Q-in-Q tagging for this.

For large scale networks, h-VPLS is a good and scalable choice.

VPLS Architecture, Partialy Full Mesh

Basic h-VPLS Architecture, Partialy Full Mesh

Advantages and Disadvantages of h-VPLS

h-VPLS (Hierarchical VPLS) has many advantages if you compare with flat VPLS. h-VPLS has also some disadvantages. Lets check the advantages of h-VPLS.

• Adding customer node to the network is simplified,
• Improved Scalability
• Efficiant Bandwith usage
• Reduced Signalling
• Simple Management
• Less packet replication

What about disadvantages? Such an efficient architecture has also some disadvantages. The complexity of the h-VPLS design and the difficulties of loop control are the main two disadvantage of h-VPLS. But for Service Providers, h-VPLS has an important role. So, they have to handle this difficulties.

Other VPLS Articles…

VPLS (Virtual Private LAN Service) – Part 1
VPLS (Virtual Private LAN Service) – Part 2 (Alcatel-Lucent VPLS Configuration)
VPLS (Virtual Private LAN Service) – Part 3 (h-VPLS)
VPLS (Virtual Private LAN Service) – Part 4 (VPLS versus h-VPLS)
VPLS (Virtual Private LAN Service) – Part 5 (Cisco VPLS Configuration)

Youn can join OUR Facebook Group with the below links!!!

About the Author
Gokhan Kosem is a telecommunation and network engineer. His ambition to IP networks and end-to-end system installation made him to prepare this web-site. By sharing his experiences about various networking protocols beside different system installation experiences and Cisco, Juniper, Alcatel-Lucent devices configurations, he is aimed to be helpful for his collegues in all over the world. He is currently lives in Istanbul, Turkey.

Leave a Reply

Copy Protected by Chetan's WP-Copyprotect.