CHICAGO--Juniper Networks is introducing four new modular Ethernet interface cards for its M- and T-series routers this week designed to help carriers migrate to Ethernet services at their own pace.

The line cards offer quality-of-service features that identify various traffic types and assign them a hierarchy, protecting the most important traffic when networks get congested. These QoS controls allow carriers to oversubscribe their networks, making more efficient use of their infrastructure rather than wasting excess capacity to avoid congestion.

“Typically today, access switches aren’t fully loading their uplinks,” said Tom DiMicelli, Juniper’s product marketing manager. “Say you’ve got a 1 Gb/s uplink averaging 200 Mb/s of traffic but spiking to 400 Mb/s. You have the opportunity to overprovision there so that, instead of five 1 Gb/s ports, you can support it with one.”

Of the four new cards, two are designed for line-rate speeds (an eight-port gigabit Ethernet card and a one-port 10-gigabit Ethernet card) and two allow oversubscription: a four-port gigabit Ethernet card (capable of four-to-one oversubscription) and an eight-port gigabit Ethernet card (capable of two-to-one oversubscription).

Oversubscription will happen more typically in Juniper’s M-series gear at the IP edge, where it aggregates traffic from access networks and even other aggregators. In core networks, Juniper’s T-series routers will likely employ line rates rather allow oversubscription, but the use of the new cards there will allow carriers to establish more consistent end-to-end Ethernet networks, DiMicelli said.

The cards can also be programmed with downloadable software to adhere to new Ethernet standards as they emerge.

Analysts have been long been calling for Juniper to add more Ethernet functionality to its portfolio, especially as its rival, Alcatel, has made advances in the edge networking market with a combination of Ethernet switches and IP routers.