Which three technologies enable lossless Ethernet? (Choose three.)
A. Priority Flow Control
B. Enhanced Transmission Selection
C. Ethernet Credits
D. Congestion Notification
E. VLAN-Aware Transmission
F. IP Type of Server Field
Correct Answer: ABD
Explanation/Reference:
Explanation:
Currently, the distinct interconnect technologies transport different traffic from different applications. The primary Ethernet extensions are as follows:
Priority Flow Control (PFC) allows definition of up to eight user priorities on a single physical link, each of which has its own logical lane that can be paused independently of the others. This capability allows a port to send a Pause frame for a given class of service that requires a lossless transmission without affecting other traffic. For example FCoE traffic uses PFC to create a lossless transmission path. This capability enables lossless 10 Gigabit Ethernet.
Enhanced Transmission Selection (ETS) allocates bandwidth among different traffic classes to help ensure appropriate priority and latency for traffic that requires it (for example, to help ensure that bandwidth requirements are met for storage traffic). The mechanism is flexible enough to allow other traffic classes to use idle allocated bandwidth, helping ensure overall efficient use of network resources.
Data Center Bridging Exchange (DCBX) is a management protocol that allows Data Center Bridging capable switches to work transparently with conventional Ethernet switches by dynamically discovering the capabilities of peer devices on the network. For example, DCBX enables an edge switch to discover the related capabilities of its peers, so that it knows how to interact with them. DCBX also allows devices to verify that configuration parameters such as user priorities are compatible among devices and to send those parameters out to peers as needed.
Reference: http://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/white_paper_c11-501770.html
Explanation/Reference:
Explanation:
Currently, the distinct interconnect technologies transport different traffic from different applications. The primary Ethernet extensions are as follows:
Priority Flow Control (PFC) allows definition of up to eight user priorities on a single physical link, each of which has its own logical lane that can be paused independently of the others. This capability allows a port to send a Pause frame for a given class of service that requires a lossless transmission without affecting other traffic. For example FCoE traffic uses PFC to create a lossless transmission path. This capability enables lossless 10 Gigabit Ethernet.
Enhanced Transmission Selection (ETS) allocates bandwidth among different traffic classes to help ensure appropriate priority and latency for traffic that requires it (for example, to help ensure that bandwidth requirements are met for storage traffic). The mechanism is flexible enough to allow other traffic classes to use idle allocated bandwidth, helping ensure overall efficient use of network resources.
Data Center Bridging Exchange (DCBX) is a management protocol that allows Data Center Bridging capable switches to work transparently with conventional Ethernet switches by dynamically discovering the capabilities of peer devices on the network. For example, DCBX enables an edge switch to discover the related capabilities of its peers, so that it knows how to interact with them. DCBX also allows devices to verify that configuration parameters such as user priorities are compatible among devices and to send those parameters out to peers as needed.
Reference: http://www.cisco.com/c/en/us/products/collateral/switches/nexus-5000-series-switches/white_paper_c11-501770.html