Port Types

Ethernet — Supported Ethernet port types include:

Fast Ethernet (10/100BASE-T)
Gb Ethernet (1GbE, 1000BASE-T)
10 Gb Ethernet (10GbE, 10GBASE-X)
40 Gb Ethernet (40GbE)
100 Gb Ethernet (100GbE)

Router ports must be configured as either access, hybrid, or network. The default is network.

Access ports — Configured for customer facing traffic on which services are configured. If a Service Access Port (SAP) is to be configured on the port or channel, it must be configured as an access port or channel. When a port is configured for access mode, the appropriate encapsulation type must be configured to distinguish the services on the port or channel. After a port has been configured for access mode, one or more services can be configured on the port or channel depending on the encapsulation value.

Network ports — Configured for network-facing traffic. These ports participate in the service provider transport or infrastructure network. Dot1q is supported on network ports.

Hybrid ports — Configured for access and network-facing traffic. While the default mode of an Ethernet port remains network, the mode of a port cannot be changed between the access, network, and hybrid values unless the port is shut down and the configured SAPs or interfaces are deleted. Hybrid ports allow a single port to operate in both access and network modes. The MTU of a port in hybrid mode is the same as in network mode, except for the 10/100 MDA. The default encapsulation for hybrid port mode is dot1q; it also supports QinQ encapsulation on the port level. Null hybrid port mode is not supported. After the port is changed to hybrid, the default MTU of the port is changed to match the value of 9212 bytes currently used in network mode (higher than an access port). This is to ensure that both SAP and network VLANs can be accommodated. The only exception is when the port is a 10/100 Fast Ethernet. In those cases, the MTU in hybrid mode is set to 1522 bytes, which corresponds to the default access MTU with QinQ, which is larger than the network dot1q MTU or access dot1q MTU for this type of Ethernet port. The configuration of all parameters in access and network contexts continues to be done within the port using the same CLI hierarchy as in existing implementation. The difference is that a port configured in mode hybrid allows both ingress and egress contexts to be configured concurrently. An Ethernet port configured in hybrid mode can have two values of encapsulation type: dot1q and QinQ. The NULL value is not supported because a single SAP is allowed, and can be achieved by configuring the port in the access mode, or a single network IP interface is allowed, which can be achieved by configuring the port in network mode. Hybrid mode can be enabled on a LAG port when the port is part of a single chassis LAG configuration. When the port is part of a multi-chassis LAG configuration, it can only be configured to access mode because MC-LAG is not supported on a network port and consequently is not supported on a hybrid port. The same restriction applies to a port that is part of an MC-Ring configuration.

For a hybrid port, the amount of the allocated port buffers in each of ingress and egress is split equally between network and access contexts using the following config>port>hybrid-buffer-allocation>ing-weight access access-weight network network-weight [0 to 100] and config>port>hybrid-buffer-allocation>egr-weight access access-weight network network-weight commands.

Adapting the terminology in buffer-pools, the port’s access active bandwidth and network active bandwidth in each ingress and egress are derived as follows (egress formulas shown only):

total-hybrid-port-egress-weights = access-weight + network-weight
hybrid-port-access-egress-factor = access-weight / total-hybrid-port-egress-weights
hybrid-port-network-egress-factor = network-weight / total-hybrid-port-egress-weights
port-access-active-egress-bandwidth = port-active-egress-bandwidth x
hybrid-port-access-egress-factor
port-network-active-egress-bandwidth = port-active-egress-bandwidth x
hybrid-port-network-egress-factor

WAN PHY — 10 G Ethernet ports can be configured in WAN PHY mode (using the ethernet xgig config). When configuring the port to be in WAN mode, you can change specific SONET/SDH parameters to reflect the SONET/SDH requirements for this port.

SONET-SDH and TDM — Supported SONET-SDH and TDM port types include:

n*DS-0 inside DS-1/E-1
DS-1/E-1DS-3/E-3
OC3/STM-1
OC12/STM-4
OC48/STM-16
OC192/STM-64 SONET/SDH
OC768/STM-256

A SONET/SDH port/path or a TDM port/channel can be configured with the following encapsulations depending on the MDA type:

Frame Relay
PPP
cHDLC

ATM — Some MDAs support ATM encapsulation on SONET/SDH and TDM ports. The ATM cell format and can be configured for either UNI or NNI cell format. The format is configurable on a SONET/SDH or TDM port/channel path basis. All VCs on a path, channel or port must use the same cell format. The ATM cell mapping can also be configured on per-interface basis for either Direct or PLCP on some MDAs (for example ASAP MDA).

Several Media Dependent Adapters (MDAs) support channelization down to the DS-0 level. ATM, Frame Relay, PPP, and cHDLC are supported encapsulations on channelized ports.

Link Aggregation (LAG) — LAG can be used to group multiple ports into one logical link. The aggregation of multiple physical links allows for load sharing and offers seamless redundancy. If one of the links fails, traffic is redistributed over the remaining links.

Multilink Bundles — A multilink bundle is a collection of channels on channelized ports that physically reside on the same MDA. Multilink bundles are used by providers who offer either bandwidth-on-demand services or fractional bandwidth services (fraction of a DS-3/E-3 for example). Multilink bundles are supported over PPP channels (MLPPP) and ATM channels (IMA).

APS — Automatic Protection Switching (APS) is a means to provide redundancy on SONET equipment to guard against linear unidirectional or bidirectional failures. The network elements (NEs) in a SONET/SDH network constantly monitor the health of the network. When a failure is detected, the network proceeds through a coordinated pre-defined sequence of steps to transfer (or switchover) live traffic to the backup facility (called protection facility.) This is done very quickly to minimize lost traffic. Traffic remains on the protection facility until the primary facility (called working facility) fault is cleared, at which time the traffic may optionally be reverted to the working facility.

Bundle Protection Group (BPGRP) — A BPGRP is a collection of two bundles created on the APS Group port. Working bundle resides on the working circuit of the APS group, while protection bundle resides on the protection circuit of the APS group. APS protocol running on the circuits of the APS Group port monitors the health of the SONET/SDH line and based on it or administrative action moves user traffic from one bundle to another in the group as part of an APS switch.

Cross connect adapter (CCA) — A CCA on a VSM module interconnects the egress forwarding path on the IOM directly to the ingress forwarding path. This eliminates the need for the physical port MAC, PHY, cable and other MDA-specific components producing a less costly and more reliable adapter.

Optical Transport Network (OTN) — Including OTU2, OTU2e, OTU3, and OTU4. OTU2 encapsulates 10-Gigabit Ethernet WAN and adds FEC (Forward Error Correction). OTU2e encapsulates 10-Gigabit Ethernet LAN and adds FEC (Forward Error Correction). OTU3 encapsulated OC768 and adds FEC. OTU4 encapsulates 100-Gigabit Ethernet and adds FEC.

Connector — A QSFP28 (or QSFP-DD) connector that can accept transceiver modules including breakout connectors to multiple physical ports. For example, a QSFP28 connector can support ten 10 Gb Ethernet ports. The connectors themselves cannot be used as ports in other commands, however, the breakout ports can be used as any Ethernet port.