Bandwidth from Access Layer to Distribution Layer

Folks:
I am currently on Chapter 12 of “CCNP Switching 642-813, Official Certification Guide” ISBN: 978-1-58720-243-8. I am currently not grasping the three layers entirely, and I was hoping someone could offer insight in a different way.
I believe I understand, that switches in the Access-Layer can be layer2 devices (2950, etc), and devices in the Distribution Layer should be Multilayer devices such as Layer-3 switches (3750) and inter-vlan routing takes place at the Distribution layer. But what I do not understand – how does one account for bandwidth and traffic from the Access Layer switches to the Distribution Switches?
Let use a 24 port 2950 switch located at the Access-Layer. If everyone was online and communicating, the total traffic for the switch would be 4.8 Gbps. The latter is due to each port providing 100 Mbps but in Full-Duplex, so (100*2)*24. So, how does an engineer spec out the required uplink ports from the Access Layer to the Distribution?
I am sure this is easy; however, I am not getting the concepts. Any insight is great.

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Posting
As noted by Peter, edge hosts don't generally all concurrently push/pull their full port bandwidth for substained periods. However, host bandwidth usage often varies much by "kind" of host. For example, many server hosts are "busier" than most user hosts, so when designing networks you normally design for lower oversubscription ratios for server hosts than for user hosts. Old rule-of-thumbs ratios suggest oversubscription ratios of about 8:1 to 4:1 for servers, and about 48:1 to 24:1 for users.
Keep in mind that oversubscription ratios can be "skewed" by what the host is doing, i.e. not all server or user hosts have similar bandwidth demands. For example, your primary mail server or primary file server might be much "busier" than other server hosts. Likewise, some user hosts might be much "busier", for example, years ago I supported a LAN segment of CADD (20) workstations which had more traffic on their local LAN than the (2,000 user) corporate backbone.

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Layer 3 to the Access Layer and MPLS Design Considerations

Hi,
We are about to install a new network consisting of Cat 4500s with Sup7E at the Access Layer, with Nexus 7000 at the Distribution and Core layers.
We have 14 floors with at least three 4500s on each floor. Within the office block where the Access Layer and Distribution Layer reside we need to support secure borderless networking using 802.1x to place users from different parts of the business into segregated networks at layer 3.
All switches will have the feature sets to support MPLS/ VRF / OSPF / EIGRP / BGP etc.
We quickly dismissed the idea of using VRF-Lite due to the sheer number of Vlans we would need to managage and maintain, the point to point links alone just to get one additional VRF on each floor required far too many Vlans.
As a result we are now considering deploying MPLS. The obvious benefits include scalability and manageability, the fact that all switch to switch links can now be routed, instead of having to using SVIs.
My query is one of design surrounding MPLS and how this maps to an enterprise network with a routed access layer. Do Cat 4500s become the CEs and take part in MPLS / BGP and Label Distribution, or does the BGP peering and Label Distribution only occur between the Distrubtion - Core - Distrubtion layers, mapping to the PE - P - PE topology in an ISP environment, the access layer simply uses the IGP (OSPF in this case) to learn routes ?
Any help would be greatly appreciated.
Chris.

Hi Andy,
Thanks for your response.
I have been doing a little bit more research it seems the Cat 4500s do not support MPLS!! Nor do Cisco have any plans to support it on this platform. I find this a little rediculous considering the level that Cisco are pitching this platform. With the Sup 7E only VRF Lite is supported, with plans to support EVN (which still uses trunk links for logical separation).
So it looks like we are going to have to go back to the drawing board.
(perhaps we should have gone HP or Juniper!)
Chris.

6500 access layer QoS

I have 6506E Sup32 PFC3B 12.2(18)SXE device at the access layer of the network and would like to implement QoS (for access ports) for Voice, Video.
I suppose that untrusted microflow policing is best for me. But documents say that such kind functionality works for L3 MSFC routed traffic. For PFC3b I can use "mls qos bridged" for bridged traffic on specified vlans. Does it really work for input service policy on access ports for traffic from user ports (if I use this command on user's int VLAN)?
Distribution and core layers of my networks are MPLS based.
Config:
interface FastEthernet2/1
switchport
switchport access vlan 10
switchport mode access
switchport voice vlan 30
no ip address
spanning-tree portfast
service-policy input IPPHONE+VIDEO
interface Vlan30 ! also for Vlan 30
ip vrf forwarding VOICE
ip address 10.168.8.254 255.255.255.0
ip helper-address 10.168.2.33
ip helper-address 10.168.2.34
ip pim sparse-dense-mode
mls qos bridged
policy-map IPPHONE+VIDEO
class VOICE
police flow mask src-only 320000 8000 conform-action set-dscp-transmit ef exceed-action drop
class VIDEO-INTERACTIVE
police flow mask src-only 2400000 8000 conform-action set-dscp-transmit af41 exceed-action drop
class CALL-SIGNALING
police flow mask src-only 32000 8000 conform-action set-dscp-transmit cs3 exceed-action policed-dscp-transmit
class class-default
police flow mask src-only 5000000 8000 conform-action transmit exceed-action policed-dscp-transmit

This URL should help you:
http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00801c8c4b.shtml

Retrieving lists from other layer into a JSP page - Design Question

Hi all,
What should be a good design technique in order to allow a JSP page to present some list obtained from other layer of my application. I intend to leave only presentation logic in the JSP layer, while all data access will be in other layer.
For example, I have a JSP page that will show the results of a SQL query originated from an entry form in other JSP page. Let's name them 'search.jsp' and 'result.jsp'
I want that all JDBC access be done in some other layer.
Question 1:
What would be better for this task? A servlet or a bean? (A bean, I suppose?)
Then this bean (?) would have to find some way to pass all the result set into this 'result.jsp'. I think it would be very poor design if I used some Data Object, because it would have to store all rows and pass them at once.
I don't want, either, that the presentation (JSP) layer access directly the data access layer (JDBC, files...). This way, I don't want any JSP page accessing the Resultset object directly.
Question 2:
What do you think could be a good design technique?
I thought of some intermediate layer that provided data objects and data access interfaces. I mean, as my data will come from different sources, like some database (JDBC), some Electronic Document Manager, I thought of having a common access interface, that would provide methods for accessing the resultsets. This could be even a java.util.Enumeration that has a hasMoreElements() method that could be implemented as the next() method from JDBC result sets and the nextElement() method that would actually bring the next row of data.
This way the JSP layer would see only hasMoreElements() and nextElement() methods from the middle layer. On the other hand, the data layer would provide as many different implementations to this access interface (Enumeration?) as there were data sources (JDBC, Files, ...)
Question 3:
What do you think of this design?
Question 4:
Is there any flaw in my approach? Which?
Question 5:
Could you suggest other designs?
I really thank you all, for any kind of answer. I actually use this design for development, however I've never seriously discussed it with someone... this is going to be of great value for me.
Regards,
Filipe Fedalto

Well I saw you question and I'll tell you what I do.
I have JSP's which post form data to servlets.
The servlet then calls a factory to produce a ResultContainer (analagous to your lists) which is generated
via JDBC, and/or request parameters etc...
this provides a single point of reference and a "group" of containers (functions really) that can be produced and reused (same container different amount of data)
I also have other static classes which can manipulate the data in the containers
(such as add additional info to the items in the containers) before I forward the container (request attribute)
to the JSP page
Additionally I use Type safe constants for all my HTML form tag names (easier to change and ensure the same name is used everywhere when reading parameters) and again for item statuses
and any other info I need to send along with the page (using Javascript to update the
status to another type safe constant).
I've found that using factories for ResultContainers is very worthwhile and allows you to implement additional servlets extremely quickly (mostly reusing containers that exist) and since the
container is the same for all my JSPs (this may not be the case with you) I can implement JSP's
very quickly as well (just change the view)
btw I refrain from calling my ResultContainer a bean because it is not serializable
I don't know if this will help but at least it gives me a forum to test my ideas
Thanks

Calculating oversubscription on access layer

So, the situation is that we have about 240 users (max, no further expansion to this figure) on each floor of a building, spanning across 10 floors. As I understood from the basic calculation, for every 240 users @ 100/1000, I need to deploy 5(48 port stacked switches within each IDF on each floor) (5x48) will share 2x1GigE uplinks(etherchannel) terminated into two different cores with a redundant 2x1G uplink (passive).
Someone tells me that this will result in an oversubscription ratio of 120:1 in the best case scenario when we fully utilize both uplinks in an active/active setup. Is this ratio unacceptable at access layer?
Should I consider dual 10GigE uplinks from the access layer to core, to start with, irrespective?
I currently am working with 1G uplinks and don't see any major hassles. My applications though utilise 3D and CAD drawings but I still feel that 2-4Gig uplink would be more than sufficient for me as I can link aggregate further upto 8Gigs using Cisco Cat 3750E.
Should we go for 10Gig uplink straightway?
Your thoughts!!

You really need to look at your traffic endpoints to determine what the possible bottlenecks are. If most of your users are only going to a couple of servers, then it's likely the bottleneck will be the server links, not you access uplinks.
With that in mind, a 10 gig link works better than channeled gig links. First, you don't have the problem of multiple flows using the same saturated gig link of a bundle while others are not being used. Second, you don't need to concern yourself that the correct channel hash method is being used.
Although 10 gig ports are more expensive than gig ports, if you factor in the possible need for additional cable runs and the cost of multiple gig modules, 10 gig might becomes less expensive sooner then you might expect.
You note you don't have any problems with gig uplinks today. Assuming your moving users from 10/100 to 10/100/1000 and they will be using 1000, unlikely performance will be any worse, but possible it won't improve much either.
PS:
Deja-vu - reminds me of moving from 10 to 100 Mbps for users and 100 to gig for uplinks

Data Access Layer In BPM

Hi,
I am using WLPI. I need to define the data access layer. As workflows deal in
XML and for JDBC calls I need value objects. I have few questions:
Is there any proffered way of communication between BPM and database?
Does BEA/Sun/BPM Users recommend entity beans for data access thru BPM?
Do I have to write XML to value object and vice versa logic for each type of communication?
Please recommend a standard approach.
Thanks,
Parag

My questions are:
Is it proper to use AI Adaptors for normal database storage? and is there any
way to store the XML into its db representation? I was thinking of calling business
operation from BPM, passing the xml and parsing it in session bean and make jdbc
calls in ejb. Looks like a lot of effort. Hence I am curious to know other solutions
Thanks,
Parag
"Dharnidhar Vemuri" <[email protected]> wrote:
Hi,
Ways that I can think of are
- using Application Integration, specifically views (it also
uses
EJB)
- EJB classes
- a java class
I didn't get u what u meant by XML to value object. Can u be in more
detail.
Thanks
Dhar
"Parag" <[email protected]> wrote in message
news:[email protected]..
Hi,
I am using WLPI. I need to define the data access layer. As workflowsdeal
in
XML and for JDBC calls I need value objects. I have few questions:
Is there any proffered way of communication between BPM and database?
Does BEA/Sun/BPM Users recommend entity beans for data access thruBPM?
Do I have to write XML to value object and vice versa logic for eachtype
of communication?
Please recommend a standard approach.
Thanks,
Parag

802.1x Guest Vlan and Routed access layer design

Hi!
For many reasons, I have to re-design my campus network in a more ISP like way. The plan is to move to a routed access layer in the next two years. I have 802.1x with guest vlan on my access ports(3750). I was reading on the subject and I found that the guest vlan feature was not availeble with internal vlan(routed port).
Is this limitation realy there, is there a way I can get around it without complicating my design even more. Do cisco have plan to lift this???

You cannot use/configure 802.1X on a routed port today. Typically, 802.1X is to be used for LAN edge ports.
The Guest-VLAN should work with a routed access design though. If your Guest-VLAN is chosen to be separate from say otherwise statically configured access VLANs, you would need to configure it via separate SVI with corresponding IP info (in a routed access model).
Hope this helps,

Since installing the latest update of Photoshop CC two days ago, Auto Blend for focus stacking is selecting all pixels from the bottom layer instead of selecting the ones in best focus from each layer. Has anyone else seen this problem?

I installed the latest update of Photoshop CC two days ago on my Macbook Pro, and now when I try to do focus stacking by opening multiple photos and doing Auto Align and Auto Blend, the blend selects the entire bottom layer instead of selecting the in-focus areas from each layer. I even tried again on a series of images where this worked a week ago and the problem occurs. I have Photoshop on a Windows 8 machine and did not apply this latest update and it works fine. Has anyone else encountered this?

And since installing this same update, my Photoshop is crashing just after starting.
Ashutosh.Nigam suggested me in this forum to change the permissions to SLStore & SLCache Folder, but it did not work.
Ali from french Adobe support told me to delete my Settings files, but it was not enough.
A girl with no name from the same team told me to update my video card driver, but you know I run the latest Mac OS X version and everything is updated, mademoiselle.
Stephane sent me a link to a huge page of things to do :
- Troubleshoot account-specific fonts, but there wasn't any corrupted font
- Delete account-specific Adobe cache files but... guess what...
- Troubleshoot account-specific login items but... yes, that's it, I can see you understand me
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I did all of these things because when I tried to open PhCC in an other admin session, it worked, so that was an incompatibility between my session and PhCC. But, but, but, when I tried again to lauch the app in the second session, it worked fine but refused to quit. Ha ha ha.
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I didn't change anything but Photoshop on my session and they ensure that the bug is due to my session and not to their update. Strange affair.
Good luck,
JLuc

What's the keyboard shortcut for "Extrusion from Text Layer"? (Mac CS6)

I keep triggering this by accident and can't figure out what combo I'm hitting, or how to disable it. I've looked in the Keyboard Shortcuts but can't find it.
I'm on a laptop keyboard, so I use the fn key a lot to access enter when I'm finished editing text. Every once in a while (but often enough to be annoying), I attempt to enter out of text editing and suddenly everything stops, the gray rotating "processing" cursor appears, and for a few seconds I'm in a mild panic about how long it's been since I saved. Then a dialog box comes up asking if I want to switch to the 3D workspace or something. Clicking "no" doesn't stop the unwanted 3D thing from happening, and the last History item then says "Extrusion from Text Layer." I then Undo and go on with what I was doing.
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Trial-and-error prevails: It's fn + shift + return. (Or shift + enter on a full keyboard, I suppose? Unless that still does a soft line break like shift + return.)
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Flex/Coldfusion data access layer

Hi
I'm researching ways to achieve a data access layer using flex/coldfusion.
Currently it seems that I would need a RemoteObject on each flex component that will access ColdFusion (a cfc that will access a database).
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So far I've only found articles describing a need to have a layered structure when building a large data-centric application, however no examples of how this is actually acheived.
If anyone has seen any examples of this please could you share them here.
Thanks.

I am looking for something similar, but I am not too
sure how it would work.
I have tried developing one myself, using the
underlying interface classes, but I am unsure how to
overcome the differences between SQL Server and
Oracle when returning result sets. SQL Server is
happy to return a DataSet from a stored procedure,
but Oracle must be given a Ref Cursor variable
parameter for each DataTable returned.
This means that the calling code must differ between
SQL Server and Oracle.
If anyone can suggest a neat way to get over this,
I'd appreciate it.
Check out the DAABv3 from GotDotNet. It implements an abstract factory pattern for data providers. It works with Oracle, but not, I think, with ODP.NET. It's extensible, though, so ODP.NET support could be added.
In addition the V2 of the .NET framework will have an abstract factory pattern for data providers built in.
On the particular question of ref cursors and Sql Server, here's what I do. My Oracle procedures which return result sets always return only one, and, by convention, the ref cursor parameter is the last one. Then I use a helper method like FillDataTable, or ExecuteReader to interface with the database. The application is bound the SqlServer definition of the procedure, but in the Oracle version of the helper function I simply add another parameter to the end of the command parameters to receive the ref cursor.
David

Data Access Layer

Hi:
Does anyone have a provider independent .net data access layer including odp.net?
Thanks
Ram

I am looking for something similar, but I am not too
sure how it would work.
I have tried developing one myself, using the
underlying interface classes, but I am unsure how to
overcome the differences between SQL Server and
Oracle when returning result sets. SQL Server is
happy to return a DataSet from a stored procedure,
but Oracle must be given a Ref Cursor variable
parameter for each DataTable returned.
This means that the calling code must differ between
SQL Server and Oracle.
If anyone can suggest a neat way to get over this,
I'd appreciate it.
Check out the DAABv3 from GotDotNet. It implements an abstract factory pattern for data providers. It works with Oracle, but not, I think, with ODP.NET. It's extensible, though, so ODP.NET support could be added.
In addition the V2 of the .NET framework will have an abstract factory pattern for data providers built in.
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David

Packets dropped to Access layer switch???

We have a 6509 running in Native IOS that has 2gb port channels connecting to our 7 access layer switches. About a week ago we were working with Remote span vlans and added a remote span from the 6509 to our other core (6513) which is connected via a 20Gbps portchannel. We began to notice that a lot of people were calling in reporting devices as being slow and we noticed that from the 6509 (Which was the root bridge) we were disgarding millions of packets on the transmit side of our access layer switches. We took out the remote span but it appears that we are still disgarding packets. There are no input or output errors on either side. The Remote span VLAN does not exist on the access layer switch's VLAN database. Does anybody have any idea what we should be looking for?

you can use an acl to match the number of packets that come into / out of each of the devices. Simply use two lines in each acl where on the first line you match the packet in question and on the second line you have "permit ip any any" so you don't block any packets. Then simply apply the acl either inbound or outbound on the interface in question. If you want more than one acl on a given device, such as inbound one interfaceand outbound another, be sure to use two different acl numbers.
create the acl's and apply them
ensure there isn't an active call
clear access-list counters on all devices where you configured the acl's so we ensure all of them are set to 0

How do I use "Trim Paths" after "Create Shapes from Vector Layer" on a strokes only layer?

Hello,
Adobe After Effects CC
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Version 13.0.2.3
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How do I get it to animate just the stroke, and not show a fill at all?
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Thanks,
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I have Googled this but not a single answer seems to work.
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Next I press Command-C.
Then I click on the layer In the Layer Panel) where I want to paste the text.
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WHY??????
Perhaps more importantly, HOW do I copy text from one layer to another?

First thing you can simply right click on the Text Layer and choose Duplicate Layer. But that will create a new Text Lay
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Edit>Copy.
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How do I copy and paste vector art from one layer to another, keeping all of its attributes?

When I copy a vector shape from one layer to another, the shape picks up the color attributes of an existing shape in the second layer (or sometimes only the outline of the shape appears). What to I do to avoid this from happening (I just just want to paste the shape in its original form and color)?

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Bandwidth from Access Layer to Distribution Layer

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