Services
7750 SR OS Services Guide Page 41
SAP Encapsulation Types and Identifiers
The encapsulation type is an access property of a service Ethernet port or SONET/SDH or TDM
channel. The appropriate encapsulation type for the port or channel depends on the requirements
to support multiple services on a single port/channel on the associated SAP and the capabilities of
the downstream equipment connected to the port/channel. For example, a port can be tagged with
IEEE 802.1Q (referred to as dot1q) encapsulation in which each individual tag can be identified
with a service. A SAP is created on a given port or channel by identifying the service with a
specific encapsulation ID.
Ethernet Encapsulations
The following lists encapsulation service options on Ethernet ports:
• Null — Supports a single service on the port. For example, where a single customer with a
single service customer edge (CE) device is attached to the port. The encapsulation ID is
always 0 (zero).
• Dot1q — Supports multiple services for one customer or services for multiple customers
(Figure 7). For example, the port is connected to a multi-tenant unit (MTU) device with
multiple downstream customers. The encapsulation ID used to distinguish an individual
service is the VLAN ID in the IEEE 802.1Q header.
• QinQ — The QinQ encapsulation type adds a IEEE 802.1Q tag to the 802.1Q tagged
packets entering the network to expand the VLAN space by tagging tagged packets,
producing a double tagged frame.
To Next Page
Loading...
