questions about new product 4928-10G

[referinfo]

in the video datasheet,4928-10G is introduced to be used in the collapsed distribution/core.but i have some questions:

1 what's the requirement of the collapsed distribution/core layer,i noticed that the full line rate is one requirement ,but is there some others?

2 what's the difference between 4928-10G and ME4924-10G,they are exactly same form factor.

3 3560E is also full line rate,can 3560E take the same role as 4928-10G in the collapsed distribution/core?why?

4 why 4928-10G's ports are all fiber?why copper port is not used here?

5 how about the market size of the collapsed distribution/core,dose someone this?

thanks

[Joseph W. Doherty]

"1 what's the requirement of the collapsed distribution/core layer,i noticed that the full line rate is one requirement ,but is there some others? "

I wouldn't agree there's always a need for collapsed distribution/core device to support full line rate. I.e. device's performance capability should correspond with expected traffic load.

Other requirements might include things to avoid failure (such as dual power supplies) and a feature set to support functions commonly performed at both distribtion and core levels.

"2 what's the difference between 4928-10G and ME4924-10G,they are exactly same form factor. "

At the hardware level, I see the fomer's switch capacity is listed as 96 Gbps and the latter's as 48 Gbps. But I would suspect more differences at the IOS level. For instance, the latter's Enterprise Image notes support for AppleTalk and IPX, the former doesn't.

"3 3560E is also full line rate,can 3560E take the same role as 4928-10G in the collapsed distribution/core?why? "

It might but again the IOS feature set might be different. For basic L2/L3 switching/routing differences might not be important.

"4 why 4928-10G's ports are all fiber?why copper port is not used here? "

My guess would be probably some combination of Cisco expectation that most initial 10 gig runs would be fiber and/or product design before/concurrent with Cat6a. The 10 gig ports do support copper using CX4.

"5 how about the market size of the collapsed distribution/core,dose someone this? "

I don't know, but as specific market for collapsed distribution/core devices, that would seem a bit of "smoke and mirrors". A device such as the 4928-10G can certainly be used for other purposes then just collapsed distribution/core and other devices could be used in that role. I look more at the devices capabilities rather than how the vendor positions it for the "market".

[referinfo]

1 can you list some features that characterize the distribution/core layer?

3 What are the IOS features that make 4928-10G better than 3560E in the collapsed distribution/core?I can not figure it out.

4 the fiber port i mentioned here is not the uplink 10G port,but the down link port (28 fiber GE).Do you have some ideas on this issue?

5 4928-10G is one SKU of whole cisco 4900 series,which include 4948,4948-10G,4900M.the latter are all positioned in data center,but only 4928-10G is positioned in the branch collapsed core distribution network. i am a bit confused by this.why branch network need this?

[Joseph W. Doherty]

"1 can you list some features that characterize the distribution/core layer?"

In brief, traditionally distribtion was where L3 was first seen, so routing and ACLs, etc. For core, performance.

"3 What are the IOS features that make 4928-10G better than 3560E in the collapsed distribution/core?I can not figure it out."

Better features would be subjective. If both devices' IOS features are contained with Feature Navigator, that tool could be used for comparisons. (More so than IOS differences, the biggest difference is type of ports provided.)

"4 the fiber port i mentioned here is not the uplink 10G port,but the down link port (28 fiber GE).Do you have some ideas on this issue? "

The GE ports are SFP ports which can use copper. However, that's an expensive method to use copper. Likely the expectation is fiber would be used for longer runs and this is more likely for a device in the distribution or distribution/core roles.

"5 4928-10G is one SKU of whole cisco 4900 series,which include 4948,4948-10G,4900M.the latter are all positioned in data center,but only 4928-10G is positioned in the branch collapsed core distribution network. i am a bit confused by this.why branch network need this?"

Again, likely focus in on the type of ports the device supports. A 4948-10G would be limited by copper Ethernet distance limitions, so it's positioned as a head of rack device. The 4928-10G, with its SFP ports (that supports many fiber ports), is positioned as distribution or distribtion/core device. Feature sets and performance (for number of ports) should be about the same between them.