Oversubscription on WS-X4908-10G-RJ45

[plee-instinet]

Hi

I am looking to deploy WS-X4908-10G-RJ45. However I noticed that its production description listed them as 2:1 oversubscription in 4900M release notes and I was not able to find any document explaining more about it.     Would someone happen to have access to such document ?

Table 1 Supported Hardware for Catalyst 4900M Series Switch

Product Number (append with “=” for spares)	Product Description

WS-X4908-10G-RJ45

8 port 10 Gigabit linecard with 2 to 1 oversubscription

Thank you.

Peggy

[Rajeev Sharma]

Hey Peggy,

I am guessing that you want to understand what is 2:1 oversubscribe ratio? Correct me if i am wrong.

In simpler terms the available backplane bandwidth to this switch is 40Gig but it has 8 ports in front with 10Gig capacity, which totals out to be 80Gig so if we divide 80 by 40, it gives reminder as 2. So in this way  WS-X4908-10G-RJ45 is 2:1 oversubscribe.

HTH.

Regards,

RS.

[plee-instinet]

Hi

Thanks for your posting.

Yes that is my question.   40Gig bandwidth is per half card ?   This 2:1 oversubscription also applies to the fixed board as well as the WS-X4908-10GE cards, right?

Regards,

Peggy

[Rajeev Sharma]

Yes, indeed you are right for both the observations, and 2:1 oversubscription applies to both modular and fixed board.

Regards,

RS.

[plee-instinet]

Got it !

Thank you !

[Rajeev Sharma]

:)

Regards,

RS.

[plee-instinet]

One more question

How is the 320G switching capacity divided per slot (backplane access of 40G) on 4900M?

Feature and Description	Cisco Catalyst 4948	Cisco Catalyst 4948—10GE	Cisco Catalyst 4900M
Switching capacity	96 Gbps	136 Gbps	320 Gbps

Thanks.