In CEN, Bundling is the association of multiple flows each with different CE-VLAN IDs to a single Ethernet Virtual Circuit (EVC) whereas Service Multiplexing is the association of multiple EVCs to a UNI.
In the below figure, all the flows CEVLAN1 through CEVLAN4 are mapped to a single Ethernet Virtual Circuit (EVC). This is an example of All-to-One bundling.
In the following figure, CEVLAN1 through CEVLAN2 representing different flows are mapped to EVC1 and CEVLAN3 through CEVLAN4 are mapped to EVC2. This is an example of Bundling not All-to-One bundling. However EVC1 and EVC2 are mapped to a single UNI is an example of Service Multiplexing.
Please note that Bundling and All-to-One bundling can’t co-exist together by definition. Port based services are a good example of All-to-One bundling. However VLAN based services supports both Bundling and Service Multiplexing.
All the three attributes mentioned above are considered as UNI attributes as per Metro Ethernet Forum (MEF).
Sham Naragund : Nice document Satheesh. Have a query.Is EVPL/EVP-LAN/EV-TREE service are example of Service Multiplexing where I configure multiple EVC(no grouping)?Basically for service multiplexing do we have to group multiple EVCs?
Satheesh Kumar S : For EVPL, EVP-LAN and EVP-Tree, the service multiplexing is supported at 1 or more UNIs provided these UNIs can support multiple VLAN based services which enforce the multiple EVCs to be associated to that particular UNI.
Ravikiran Ambati : These diagrams very useful to clear most of ambiguities between Bundling, All-to-One bundling and Service Multiplexing. Thanks Satheesh.