Blocking Calls at the Gateway by Caller ID

Sometimes administrators have to block calls harassing, scam, or other undesirable calls. In newer versions of CUCM, this can be done in CUCM, or it can be done on an h.323 or SIP gateway.

Which should you use? There are good reasons to use both. Blocking on CUCM centralizes call routing, so you don’t need to touch gateways, and can be configured so that placing a number in once blocks it at all gateways. Blocking it at the gateway can be easier to implement, and stops the call at the ingress, so that no internal resources are ever used. Properly configured, blocking at the gateway will maintain protection in SRST, as well. So either way has benefits, use the one that fits into the existing environment best.

Blocking on the gateway uses translation profiles, which can be applied to the ingress port, and the inbound or outbound dial peers. Placing the blocking patterns on the port stops them right away, but may require placement on multiple ports. Continue reading

Reversible vs. Non-Reversible Encryption

Cisco devices can store passwords using either a reversible (Type 7) or non-reversible (Type 4 or 5, enabled by the “secret” keyword) encryption.

Reversible encryption has the ability to decrypt the stored password, which can then be compared to the password a user wishing to authenticate provides. Cisco Type 7 passwords are stored using reversible encryption. When you configure a password with “service password-encryption” enabled in the config, the device runs a calculation against the password, creating a string that contains the encrypted password. It is not a simple substitution cipher, but it is easily decrypted, and can even be decrypted on a router. Continue reading

Reading Data From XML Documents in UCCX

Have you ever wanted to do any of the following from a Contact Center application?

  • Read a schedule from a local document, rather than having to use script editor to edit schedules
  • Be able to load a schedule from a web server, so you didn’t even need to touch you CCX server
  • Bring in external data without UCCX Premium
  • Bring in external data from a database there isn’t a driver for

All these and more can be done by reading XML formatted data either stored in the local repository, or served from an external web server, and retrieved using the Create URL Document or Make REST Call steps. Since you are able to read from a web server, any web programing language, like PHP, ASP, or JSP, could be used to retrieve and format the data.

Once UCCX has the XML formatted data, the Get XML Document Data step uses the XPath syntax to get data out of the document. This is a powerful syntax for reading data from XML formatted documents, as we will explore here.

In this post, we will use the Make REST Call step to retrieve information from the REST interface on the UCCX server, which provides easy access to a remote source of XML formatted data. Continue reading

Impressions of the 8861

I recently had the opportunity to pick up a couple of 8861s for my lab/home phones, and thought I would do a writeup on my initial impressions. The 8800 series phones offer an updated look, and a number of new features.

The 8800 series also continues the move from soft keys to more hard keys, with hard Back, End Call, Hold, Transfer, and Conference keys added to the Voicemail, Settings (now combined with services), Directories, Headset, Speaker, and Mute buttons on the 7900 series. I don’t know how I feel about the move to more hard keys. Soft keys have the advantage that only the necessary ones are displayed, but sometimes important ones can get buried. Hard keys will also have an advantage when using apps like IP Phone Agent, since the call control soft keys are hidden by the application soft keys.

Also, in keeping with the new Cisco phone lines, they are SIP only, no option for SCCP.


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Time of Day Routing in CUCM

Time of Day routing allows for calls to be treated differently based on the time of day and day of week. This allows for things like automatically rerouting calls to a different destination when the company is closed, not allowing PSTN calls after hours, or requiring a Forced Authorization Code outside of business hours. Another real-world example I have worked with is patient rooms in hospitals, which should not receive outside calls at night.

CUCM uses the standard Partitions and Calling Search Spaces, with the addition of a Time Schedule that specifies when the Partitions will be active, to perform time of day routing. Outside the time schedule, the partition is effectively invisible to call routing. Appropriate ordering of in a CSS allows the calls to be routed to an alternate number when the partition is not available.

An important consideration in designing the Partitions and CSSs is whether you want calls to be able to route to the phone off hours at all. For instance, with the patient room example, should internal numbers be able to call the rooms, and only outside calls be blocked? We will look at two examples, one that allows for some calls to go through, one that does not.

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Initial Configuration of IOS Devices

In this post we will take a look at the initial configuration that should be performed on a new device before the actual network configuration is performed.

Most Cisco IOS devices come from the factory with a very basic default configuration, and require configuration before the are deployed. The majority come with no IP addresses, and routers even have all their interfaces shut down by default.

To begin the configuration, the first step is to console into the device, using either a serial port and the Cisco rollover serial cable, or the mini USB port on the newer devices. Console settings should be 9600 baud, 8 data bits, no parity, 1 stop bit, no flow control. You need terminal emulation software, such as PuTTY or SecureCRT.

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Practical OSI Layers – Part 2

In the previous post, we took a look at the basics of the OSI and TCP/IP model layers. In this post we are going to take a closer look at end to end routing of a packet, and the interaction between layers 2 and 3 as a packet is passed between routers to it’s ultimate destination. The following is the general process to route between endpoints. Some operating systems may behave a little different that described, but this is the general process.

This post will use this network, with a telnet session from R1 to R3. R1 is connected to R2 via a serial link running PPP, and R2 is connected to R3 via an Ethernet segment. Continue reading

Practical OSI Layers – Part 1

In this post, we are going to explore the OSI and TCP/IP layered model, and use some packet capture examples to illustrate the modular nature of the two models.

One of the most difficult subjects for many people beginning to learn networking or studying for the Network+ or CCNA certifications to grasp seems to be the 7 layer model used by the OSI model and the similar model used by TCP/IP. The two models do the same thing, but define slightly different layers. They are as follows: Continue reading

Prime License Manager

With the upgrade to Cisco UC 10, Enterprise License Manager (ELM) is “replaced” with Prime License Manager (PLM.) This is really just a rebranding of the existing ELM, although there are a few differences.

There is a standalone PLM OVA and ISO to install PLM. in 9.x, you installed a standalone ELM server from the UCM install media, and used the smallest OVA to create the virtual machine. PLM uses an even lighter footprint OVA, and has it’s own install media.

PLM is also installs co-resident with CUCM and Unity Connection. Unfortunately, it still installs automatically on every CUCM/UConn server you install. I would like to see an option so you can enable/disable PLM when you install the server, or at least only install on the publisher.

PLM 10 supports both version 9 and 10 licenses. To support version 10 licenses in ELM 9.x, you need to install a COP file (elm_LicenseDef_9_1_v1.cop.sgn) to allow ELM 9.x to recognize the version 10 licenses.

Here is more information on ELM.