A small dive into Cisco IOS

The guys at Techwise TV have a short but interesting feature on Cisco IOS




Techwise TV

SIP trunking - part 1

Recently we implemented a Vodafone SIP trunk at our office. The Vodafone setup consists of a fiberswitch and a Cisco 2901 CUBE (Cisco Unified Border Element). Normally the CUBE connects directly to a Cisco Unified Communication Manager (CUCM) but we connected it to our own CUBE mainly because of 3 reasons:

• our own CUBE enables us to control the way it talks tot the CUCM
• we need SRST on the CUBE because the SIP-trunk is not located at the CUCM-site.
• it's also the prefered way to do it  

The first thing we had to think about is: how do we connect to our CUCM? SIP or H.323? We went for SIP, also because we wanted to stay as close to the suggested setup in the Vodafone-documentation.

Researchers Find Way to Boost WiFi Performance 400-700 Percent

Is this just bringing switching tech to a shared medium? Nonetheless interesting:


WiFi hotspots in locations such as airports and large conventions frequently experience poor performance in terms of downlink goodput and responsiveness. We study the various factors responsible for this performance degradation. We analyse and emulate a large conference network environment on our testbed with 45 nodes. We find that presence of asymmetry between the uplink/downlink traffic results in backlogged packets at WiFi Access Point’s (AP’s) transmission queue and subsequent packet losses. This traffic asymmetry results in maximum performance loss for such an environment along with degradation due to rate diversity, fairness and TCP behavior. We propose our solution WiFox, which (1) adaptively prioritizes AP’s channel access over competing STAs avoiding traffic asymmetry (2) provides a fairness framework alleviating the problem of performance loss due to rate-diversity/fairness and (3) avoids degradation due to TCP behavior. We demonstrate that WiFox not only improves downlink goodput by 400-700 % but also reduces request’s average response time by 30-40 %.

http://news.ncsu.edu/releases/wms-gupta-wifi/

Dropbox alternatives

At this moment I enjoy the sharing and storing possibilities of my Dropbox account and since I got my HTC one S the amount of available storage increased to 25Gb (for 2 years). I share documents and files with my wife, family and friends. We use it for sharing files between members of our local Scouting club, etc.. And even with it's ease of use it's not enough to silence that nagging feeling: it's not your own storage.
When I find the time I think i'm going to do testsetup of Owncloud. It's free and it runs on your own server/storage.

http://owncloud.org/

For those seeking a cloudstorage option for Windows and Linux (no Mac support yet), try Ubuntu One. It gives 5 Gb instead of the free 2Gb at Dropbox.

https://one.ubuntu.com/

When speaking of cloudstorage I feel obliged to mention one of the granddadies of cloudstorage (before we started calling cloud to anything remote or a bunch of servers together) : iFolder. Developed at Novell, released in 2001 and now a open source project.

http://ifolder.com/ifolder

FreeBSD - OpenLDAP and FreeRADIUS part 2

The OpenLDAP server is running and now I have to implement the design for the directory I want to use. Before I can start entering all ou,dc,cn-info I'm going add a password for the slapd-daemon and generate a hash for in the slapd-config file. There are several hash-schemes for the password but I'm going to use the MD5-hash:

slappasswd -h {MD5}

This command asks for a password and after entering one, it generates a hash.

New password:
Re-enter new password:
{MD5}1iB8sGXpjoNB5Ra2copmjQ==
[root@fbsd-radius ~]#

Copy this hash, we're going to need it later

FreeBSD - OpenLDAP and FreeRADIUS part 1

At the moment I have a Cisco 1231 access point in use and I was wondering if I could use OpenLDAP in combination with FreeRadius to do some authentication for my wireless clients. Next to that I want a setup to test Radius authentication with an ASA 5505. Since I'm still in a FreeBSD mood and the current OpenLDAP implementation on Ubuntu is way too complex for a simple setup I decided to stay with the red daemon.

A small rant:
In the 90's I started working with Novell Directory Services/eDirectory up until version 8.8 a few years ago. Did some LDAP work on Active Directory. Had Mac OSX clients authenticate to eDirectory and AD even with drive mappings etc.. It was not always easy but we got there..... It's 2012 now,  then why do I have to enter several unreadable CLI commands (yep even unreadable for an experienced linux user) in Ubuntu just to add a Samba schema. I'm certainly not afraid of CLI but this is not the 80's anymore. If you're able to write create an ubercomplex configsystem, like the one found in the current Ubuntu-version, you're also able to write a decent tool to manage it!! 

First I created a FreeBSD setup as I described earlier (up until the installation of my favourite tools). After FreeBSD was installed I continued with OpenLDAP.

Commodore 64 - 30th anniversary

This week the Commodore 64 has become 30 years old. This computer was for a lot a people the first step into the wonderful world of computers and IT. It was my first own computer (my first experiences I had on a Exidy Sorcerer). Here are some links about the wonderful machine:

http://techcrunch.com/2012/01/02/the-commodore-64-is-30-years-old/

http://www.pcauthority.com.au/News/168019,vintage-tech-looking-back-at-the-commodore-64.aspx

http://news.cnet.com/8301-17938_105-57351005-1/commodore-64-30-years-of-wins-and-fails/

http://www.reghardware.com/2012/01/02/commodore_64_30_birthday/

http://en.wikipedia.org/wiki/Commodore_64

Cheers C64!