Introduction to Carrier Grade Cisco ASR routers: Cisco ASR 920 routers

Today I am going to talk about the carrier grade Metro ethernet routers of Cisco. These routers are very much favourite in many of the service provider or enterprise networks. If you look on to the big portfolio of cisco in carrier ethernet access and the aggregation, there are devices like Cisco ASR 902, Cisco ASR 903, Cisco ASR 907.

There are some of the high end routers for multi dimensional service scale and these routers are Cisco ASR 901s, Cisco ASR 901, Cisco ASR920 and ME1200E. Earlier some of the ethernet carrier switches like Cisco ME 2400, Cisco ME 3400/3400E, Cisco ME 3600X and Cisco ME 3800 are now end of sale and life.

So in the portfolio of carrier grade ethernet services you can go with the devices like Cisco ASR 901, Cisco ASR 902, Cisco ASR 903, Cisco ASR 907 and Cisco ASR 920 devices. Here in this article I will talk about the Cisco ASR 920 with the features and the use of the device in the Service provider carrier networks.

Fig 1.1- Cisco ASR 920 4SZ model
There are various models in Cisco ASR 920 series. The major thing you are looking for the forwarding rate and the switching capacity of the device. Cisco ASR has the capability of 128 Gbps of Fabric rate and 96 Million pps switching capacity.

Regarding the buffering and queuing, Cisco ASR 920 has 12 Mbyte on-chip packet buffering with 4k queuing. Cisco ASR 920 has three level of hierarchical queuing which are port, sub-channel and queuing.

These models are based in the number of the ports which can be 1 Gbps or 10 Gbps as required. Some of them are SFP based and some of them are copper based 1 Gbps ports. while for 10 Gbps you should required SFP+ ports.

Fig 1.2- Cisco ASR 920 models

For the MPLS label operation, Cisco ASR 920 has ability to have 5 label PUSH and 3 label POP. It has other features like BFD, CCM and multi-purpose FPGA which includes performance, testing and Net-flow. We have the below mentioned models in Cisco ASR 920 models based upon the number of the ports required.

  • ASR-920-4SZ-A and ASR-920-4SZ-D
  • ASR-920-12CZ-A and ASR-920-12CZ-D
  • ASR-920-10SZ-PD
  • ASR-920-24TZ-M
  • ASR-920-24SZ-M
  • ASR-920-12SZ-IM
  • ASR-920-24SZ-IM


If we can talk about the licensing model for Cisco ASR 920, It can be categorised in three different flavours. These are Metro Access, Metro IP access and Advanced Metro IP Access. These models are basically differentiate with each other on the based of the features.

  • Metro Access : Qos with deep buffers and H-Qos, 802.1d and 802.1q features, EVC, Ethernet OAM, Spanning tree, G.8032, REP, IPv4 and IPv6 host connectivity
  • Metro IP Access : All IP routing protocol support includes BGP, OSPF, EIGRP, IS-IS, Multicasting support PIM and SSM mapping, BFD, Multi-VRF CE, VRRPv3 support as well
  • Advanced Metro IP access: All the above mentioned features and the other features like MPLS which includes MPLS-TE and MPLS-FRR, MPLS OAM, EoMPLS, SAToP, VPLS, H-VPLS, mLDP and feature like routed VPLS.