[c-nsp] ASR920 vs ASR1001-x

Juergen Marenda cnsp at marenda.net
Sat Apr 30 07:39:25 EDT 2016

Even a 3COM 4200G is called a "layer 3 switch"
(but it's very limited : 
 " 32 static routes
    8 IP  interfaces
  Hardware based routing" 
 (from an ancient datasheet)

That's just marketing clouds ... tons of features, often mutex;
so they will not fly as a cloud should.

(The mentioned device and it's successors work quite well
for their target market as "full manageable" L2 device .)

Today, a bridge with some hardware-speed-up is called a "switch" even if it
does only store-and-forward;
"switch" was the name for such a device with "cut through" and minimal
Number of Ethernet-frame bits delay (6 Octets for the destination-MAC plus
some bits for setup up the path to the output port).

A L3 Switch would be a similar device, looking into L3 info 
 which is "later" in the paket (and sometimes on variable place to
complicate this)
so the minimum delay ( with real switching - not store-and-forward ) must be

Everything else forwarding on L3 (per "store and forward") should be just
called "router" 
even when it's quite fast due to high CPU or hardware-based acceleration.

just my 0.01 $


-----Ursprüngliche Nachricht-----
Von: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] Im Auftrag von
sthaug at nethelp.no
Gesendet: Freitag, 29. April 2016 12:36
An: mark.tinka at seacom.mu
Cc: cisco-nsp at puck.nether.net
Betreff: Re: [c-nsp] ASR920 vs ASR1001-x

> > ASR920 is more like a switch.
> Not really - it's actually a router.
> It just looks like a switch.

Interesting - one of our local Cisco distributors, in a meeting with us and
with Cisco people present, repeatedly called ASR920 a Layer 3 switch.
With no protest from the Cisco representatives.

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