MPLS MTU

Maximum transmission unit (MTU) is a well-known parameter in the IP world. It indicates the maximum size of the IP packet that can still be sent on a data link, without fragmenting the packet. Data links in MPLS networks also have a specific MTU, but for labeled packets. Take the case of an IPv4 network implementing MPLS. All IPv4 packets have one or more labels. This does imply that the labeled packets are slightly bigger than the IP packets, because for every label, four bytes are added to the packet. So, if n is the number of labels, n * 4 bytes are added to the size of the packet when the packet is labeled.

This section explains that an MPLS MTU parameter pertains to labeled packets. Furthermore, it explains what giant and baby ...

Get MPLS Fundamentals now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.