Ethernet Access (E-Access) is a Carrier Ethernet service type defined by MEF, the industry body for Ethernet services, for wholesale access between operators. One operator, the access provider, carries traffic from a customer site to a handoff with another operator, the service provider, which then delivers its own service to the end customer. E-Access is how a provider reaches a building outside its own network, and it is the usual technical form of the off-net leg of an Ethernet circuit.
At a glance
- E-Access is wholesale: one operator sells it to another, not usually to the end business.
- It connects a customer site’s interface (the UNI) to an external network-to-network interface (ENNI) between the two operators.
- MEF defines point-to-point and multipoint versions, with port-based and VLAN-based variants.
- Buyers meet it as the off-net or Type II portion of a circuit, which can affect lead time, repair and the SLA.
What problem it solves
No single provider has fiber into every building. When a business wants an Ethernet, internet or private network service at a site its chosen provider does not reach, the provider buys access from an operator that does, often the local incumbent or a regional fiber company. Without a standard way to do that, each pairing of providers would need a custom arrangement for how traffic is tagged, handed off, measured and repaired.
E-Access standardizes that wholesale relationship. The access provider delivers an agreed Ethernet service from the customer’s port to the interconnection point, and the service provider stitches it into its own network. For the business buying the overall service, it means one contract and one provider covering sites the provider does not reach on its own fiber, at the cost of a second operator in the path.
How it works
Two parties, one circuit. The access provider owns the connection to the customer building and the equipment that presents the user network interface (UNI). The service provider owns the customer relationship and the rest of the network. They meet at an external network-to-network interface (NNI), called an ENNI in MEF terms, usually in a shared facility.
Service variants. Point-to-point versions carry traffic between one UNI and the ENNI. A port-based version carries everything on the customer port, while a VLAN-based version lets several services share one customer port and one ENNI, identified by VLAN tags. Multipoint versions exist for connecting several UNIs through the ENNI, though point-to-point is more common.
Handoff and tagging. At the ENNI, traffic for many customers shares the same physical link, separated by VLAN tags. The service provider maps each one to the right customer service, such as an E-Line, EVPL, internet access or an MPLS network.
Performance and repair. The access provider commits to bandwidth and performance on its segment. The service provider is responsible to the customer end to end, but a fault on the access segment has to be handed to the access provider to fix. That is why lead times and repair times are often longer at off-net sites.
For how providers combine many access circuits into a single network, see our Network Aggregation solution page.
When it matters for buyers
- Opening a site outside the provider’s footprint. Ask whether the address is on-net or off-net. Off-net usually means E-Access or a similar wholesale arrangement, with its own lead time.
- Comparing quotes. Two providers may quote the same building using the same underlying access operator. Knowing who owns the last mile tells you whether you are really buying diversity.
- Reading the SLA. Check whether availability and repair targets apply equally to sites reached over another operator’s tail circuit.
- Troubleshooting chronic issues. Repeated faults at one off-net site may sit with the access provider, which you cannot call directly.
Questions to ask vendors
- Is this site on-net, or will you use another operator’s access to reach it?
- If off-net, which access provider will you use, and over what medium?
- Is the access port-based or VLAN-based, and how much bandwidth is committed on the access segment?
- Does your SLA cover the access portion with the same targets as the rest of the circuit?
- Who opens and tracks a ticket with the access provider, and what is the escalation path?
- If we want path diversity, can you show which sites share an access provider or route?
How it differs from E-Line
An E-Line is a point-to-point Ethernet service between two customer interfaces (UNI to UNI), sold to the end customer. E-Access runs between one customer interface and an operator-to-operator interface (UNI to ENNI), and is sold by one operator to another. A service provider often builds the E-Line a business buys by combining its own network with E-Access from another operator at one or both ends, so the business may be using E-Access without ever ordering it by that name.