Hey all! Just a quick question. I asked a few engineers at work and they weren’t too familiar with q-in-q tunneling and didn’t really have an answer.
So, my question is…
What’s the main difference between q-in-q tunneling and MPLS other than the fact that MPLS supports such things as TE w/ RSVP, ISIS, or OSPF.
Also, I know that one is using label switching and the other one is using vlan tagging.
Am I kind of thinking out of scope for the use cases of q-in-q tunneling? It kind of seems like they both try to accomplish the same thing. Distinguish customer traffic from one end to the other end.
It is true that both MPLS and QinQ are capable of segmenting the traffic of multiple customers into separate “domains” allowing an ISP to carry traffic from many customers while keeping it separate. However, there are major differences between the two.
The primary differences can probably be summed up like so:
QinQ operates at Layer 2 and only with 802.1Q Ethernet encapsulation while MPLS can operate at Layer 2 or Layer 3, and can carry multiple protocols.
QinQ must be manually configured at the physical port connecting to each customer while MPLS allows for a more dynamic configuration method. In this way MPLS is much more scalable.
QinQ uses VLAN tags to separate traffic, while MPLS uses a combination of MP-BGP, VRFs, and routing between PEs and CEs that allow for a multitude of options and configuration scenarios including overlapping IP addressing schemes and security. Just take a look at the size of the MPLS course, which covers the basics, and compare that to the single QinQ lesson.
I suggest you also go over the NetworkLessons Notes about QinQ and MPLS for more information.