Aaron Dhiman's Tech Blog

Loading Customized Background Images on Phones

2012-01-29T11:58:00.027-05:00

Creating the images

Each background image requires two PNG files:

· Full size image—Version that appears on the on the phone.

· Thumbnail image—Version that appears on the Background Images screen from which users can select an image. It must be 2 5% of "he size of the full size image. The PNG files for background images must meet the requirements for proper display on the Cisco Unified IP Phone (see table below). You can use Paint and MS Office Picture Manager to create images.

Phone Model	Full-Size Image	Thumbnail Image	TFTP Directory
7941/7961	320x196	80x49	Desktops/320x196x4
7942/7962	320x196	80x49	Desktops/320xl96x4
7945/7965	320x212	80x53	Desktops/320x212xl6
7970/7971	320x212	80x53	Desktops/320x212xl2
7975	320x216	80x53	Desktops/320x216x16

Creating the List.xml file

The List.xml file defines an XML object that contains a list of background images. The

List.xml file is case sensitive and stored in the same TFTP directory as the images it is

listing on the TFTP server.

List.xml Example:

&lt;ImageItem Image="TFTP:Desktops/320x212x16/IMAGE-THUMB.png" URL="TFTP:Desktops/320x212x16/IMAGE.png"/&gt; &lt;/CiscoIPPhoneImageList&gt;

Making the File Available

Once you have the image files and the List.xml file, you need to upload the files to the TFTP

directory specified in the above table in each TFTP server manually.

Once you upload everything, you will need to restart the TFTP service so that the files are

uploaded for the IP phones.

PROCEDURE STEPS:

Ø Log in OS Administration

Ø Go to Software Upgrades\TFTP File Management

Ø Click Upload File

Ø Browse to the .PNG image and open it. Type the directory based on the above table.

Ø Click Upload File

Ø Log on to Serviceability page to restart TFTP service.

IOS Packet Captures

2011-09-30T23:27:00.001-04:00

It's actually quite easy to do full packet captures with ACL Filters on routers. This is at times much better than relying on debugs to troubleshoot issues. Here's how (in this case a SIP Signaling Packet Capture):

1. Create Traffic Profile. Here, for SIP Signaling
!in config mode
ip traffic-export profile SIP-CAP mode capture
bidirectional
incoming access-list 123
outgoing access-list 123

access-list 123 permit udp any any eq 5060
access-list 123 permit tcp any any eq 5060

2. Apply to an interface
!in config mode
int g0/0
ip traffic-export apply SIP-CAP

3. Capture the traffic
!in enable mode
#traffic-export int g0/0 clear
#traffic-export int g0/0 start

#traffic-export int g0/0 stop

4. Export the CAP to a server using ftp or tftp
!in enable mode
#traffic-export int g0/0 copy ftp://x.x.x.x/capture.pcap

Packet Captures on Cisco UC Appliances

2011-01-30T23:06:00.003-05:00

Sometimes it's not obvious about how to get things done on the Cisco Appliance platforms, especially if you're used to the Windows platforms. But, you really can do everything you used to--you just do it differently. For instance, to get a packet capture use the CLI and enter the following command:

utils network capture eth0 file Capture1 size all count 100000

Type CTRL-C to stop the capture.

Then, you can retrieve the packet capture by using RTMT (Real Time Monitoring Tool):

In RTMT, use the Collect Files tool. Select Packet Capture Logs for the server. The PCAP File will then download to your PC, and you can open it with Wireshark.

This will work with all of the Cisco UC Appliances.

CUCM 8.0(2c) on VMWare

2010-10-16T08:42:00.001-04:00

After much trial and error, I was able to get CUCM 8.0(2c) installed on VMWare Server. In spite of only being officially supported on ESXi, it is possible to get CUCM 8 running on VMWare Server or Workstation. The best procedure to doing this is:

1. Download OVA file from Cisco and open with Text File to see recommended settings. Some of the hardware specs in the OVA file are required (e.g., dual 80 GB Hard Drives), but others are not strictly checked for during installation, like 2304 MB of RAM (2048 MB worked for me).

2. Configure a new VM with VMWare server using Red Hat Enterprise Linux 4. Any other flavor of Red Hat will not work. The following VM settings worked for me:

RHEL 4
1 CPU
Dual 80 GB SCSI Hard Drives (0:0 and 0:1)
2048 MB of RAM
USB Controller
IDE CD ROM
Ethernet Bridged
No need to pre-allocate the drives (you can let them grow as needed, though performance will suffer slightly). You can pre-allocate the drives if you want, though. It just takes much longer to set up the VM and takes away a lot of disk space unnecessarily.

You'll then get the Demo license which is good for a single node and 50 DLUs.

Aaron

CUCM 7 Features

2010-07-28T16:50:00.013-04:00

Cisco has been hard-at-work adding new features to CUCM. Here's a spreadsheet I've created with descriptions of all the new features for CUCM 7. I'll soon be publishing sheets for CUCM 7.1 and CUCM 8. Enjoy:

https://spreadsheets.google.com/pub?key=0AjU-M37pyCMfdEFtYUlWUFZlYmF3bk5NZ1lFbzFaWkE&hl=en&single=true&gid=0&output=html

CDP Holdtime and LabUpdate

2010-07-17T23:17:00.019-04:00

You may have shut down a link or suspected a link failure but seen "sh cdp neigh" still displaying an active connection, well that is all due to the CDP Holdtime. It has to run down to 0 before the neighbor is removed from the table. The default is 180 seconds, which can certainly lead to some confusion if you are troubleshooting a recently failed link. The default can be changed with the "cdp holdtime" global parameter. Once you're used to looking for it, you can see that the holdtime is unusually low for the failed link, which should lead you to figure it really is down w/out waiting for the entire holdtime to expire:

Rack1SW2#scn
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater

DeviceID   Local Intrfce Holdtme Capability      Platform      Port ID
BB2            Fas 1/0           125          R S I            3725           Fas 0/0
Rack1SW1 Fas 1/9            15            R S I            3725           Fas 1/9

Notice that the Holdtime will keep decrementing and be unusually low (15 here) which indicates you may have a problem before you'll actually see the neighbor drop off completely.

As for my R&S lab, b/c I've just taken on a new large project I'm going to have to move my lab back til next Spring. I'm just able to work through about 10 pages / day of INE Workbook 1, so it'll be a while before I finish! Once I've finished WB 1, I'll then do full labs for a couple of months before attempting the real thing.

Real Switches vs Dynamips for switching

2010-07-10T01:51:00.009-04:00

I've gone back-and-forth with whether or not to purchase real 3550 and 3560 switches for my home lab. I've decided NOT to, and to continue for now with Etherswitch modules. My reasoning for this is that I prefer renting racks for 8 hours to do real labs anyways, which allows me to switch up the rack configs and to force me to sit there and run a full lab non-stop. So, since I'll be renting racks anyways, I'll just rent some time to practice switching stuff as well. I also don't feel like spending so much extra time getting good deals on all the parts and re-configuring the lab.

Here's a list of the major features I'll be lacking with Dynamips, and they are significant:

No ISL trunking
No bpdu-guard on interfaces
No QinQ trunking
No private VLANs
No PAgP / LACP
Cannot set switch ports to nonegotiate
lose some STP features, like bpduguard, bpdufilter
No MSTP
No layer 3 port-channel
No Switch Database Templates
No udld
No port security
No port protected
lose some qos specific configuration of hardware queues like srr-queue
No extended VLANs, unless transparent mode
Can't modify prune-eligibility of ports

I'll still prefer to rent racks to get practice. Luckily, http://www.gradedlabs.com/ is pretty cheap!

Whew! Getting the hang of this.

2010-07-09T00:00:00.004-04:00

As I was planning all-along to do a hybrid of GNS3 and Lab Rentals, I went ahead and bought the standard INE workbooks (not the Dynamips version). Well, there has been a bit of a learning curve with that. I had to learn about re-mapping the ports b/c of only 16 ports on the ESW modules (as opposed to the 24 on the real 3560/3550s) and configuring all the router ports as fixed 100/FULL. Then, I had to learn to THROW AWAY the Phy Diagram, and rely on the Logical and "Sh CDP Neigh" to get the configs done! That, and not to take all of the solutions for INE Vol I too literally b/c there are some errors in the tasks and the order of the tasks may not match the verification. That only improves your troubleshooting skills though!

If you run into any of the same issues, there's plenty of discussion on the INE forum, or feel free to drop me a line. I'm once again re-assured that the INE materials will be fine...in particular b/c of the support from the instructors and forums.

I'm going to come up with a realistic schedule to finish Vol I once I get rolling and see how much I can reasonably cover each week.

Familiarize yourself with v4 Lab Interface

2010-07-07T10:32:00.001-04:00

The v4 Lab Interface is way different than in past times. In summary, here are some interesting changes:

1. New Lab Delivery System.
2. NO PAPER Lab Workbook. Everything is now on Lab Delivery System app.
3. Uses Putty WITHOUT Tabbed sessions.
4. It is a little kludgy, so get used to it!

Don't waste a lab attempt not being familiar with these important changes!

Here's a good video demo:

https://learningnetwork.cisco.com/static/video-wp/CCIE_RS_v4_Lab_Exam_Demo_640x480-v2.htm

GNS3 Up and Running

2010-07-05T00:53:00.001-04:00

I recently spent a day getting my new server (AthlonII-Quad, 4 Gig RAM, Windows 7 64-bit) up and running with the INE topology. I ran into a few snags along the way:

1. UltraVNC is the best VNC App with Windows 7, as it is a 64-bit app and runs fast. RealVNC and TightVNC are still 32-bit and are awefully slow. A few notes aboue UltraVNC:

Be sure to set a different password for the view-only Password than you do for the VNC Password
In the admin properties "disable viewers inputs" must be disabled - I had to uncheck before mouse inputs would work it worked.

2. With GNS3, I had to split the INE topology into two hypervisors to get it to work. Otherwise I could only emulate 10 routers are a time! Thanks to Mady Cisse over on the INE boards with the assist:

http://ieoc.com/forums/p/8504/106534.aspx

My settings of interest were:

mmap = False
idlepc = 0x60c05948
IOS 12.4-15-.t11

With this setup, my CPU is running around 35%. Now, time to do some real work!

CCIE R&S Preparation has Begun!

2010-07-01T16:15:00.006-04:00

Well, I've finally finished reading the glorious 1000-page CCIE Routing and Switching Certification Guide v4 by Wendell Odom, Rus Healy, and Denise Donohue, and I've passed the Written Exam; so, it's time to begin lab prep! That Odom book was really great, and I really enjoyed the IPv6 and MPLS chapters. Most of the errors I found were corrected in released Errata; however, one still has not. Don't let this trip you up: regarding 3560 Switch QoS on page 558 it states the following in regards to Egress Queues:

"Both shared and shaped mode schedulers prevent the PQ from exceeding its configured bandwidth when all the other queues have frames waiting to be sent. The shaped scheduler never allows any queue, PQ or non-PQ, to exceed its configured percentage of link bandwidth, even if that means that link sits idle."

That is really not correct, as you can see here on Cisco documentation: http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_52_se/command/reference/cli1.html#wp11909150

"The expedite queue is a priority queue, and it is serviced until empty before the other queues are serviced."

I ran this by a few other engineers, and they also agree with this assessment, that it will indeed starve the other queues unless you explicitly configure policing. I'm also surprised that the book never mentions that Spanning-Tree BPDUs are sent to the MCAST address 01:80:C2:00:00:00. There's also not much detail on QinQ tunneling, and I had to access other resources to get the config portion.

When I was preparing for the the Voice lab, I spent about 18 months! That included about 8 months to complete the CCVP, 3 months to prepare for the Written, and about 5 months of prep for the Lab. And now another journey is under way. I tentatively have a lab scheduled for Oct 2010, and I plan on going through all four INE books before then. I was shocked however to recently open up the first workbook and find 2600 pages waiting to be covered! It's gonna be a busy 6 months ahead!