Understanding Cisco Voice Gateways - Part 4. Digital Voice Ports

In the previous parts of our Cisco Voice Gateway story we identified what analog voice ports are. Also we talked about different types of analog supervisory signaling. Now let's see how we can use our Cisco voice gateways with digital lines such as T1, E1 and BRI. These types of connection are still widely available worldwide. This post maps out the various digital interfaces and explains the differences between them.

Understanding Cisco Voice Gateways - Part 3. Loop-start and Ground-start Signaling (FXS and FXO Ports)

Now you already know what Cisco Voice Gateways are and which types of analog voice ports they can use. It is time to discuss signaling processes on FXO and FXS ports. As it was shown earlier, voice ports on routers and gateways physically connect them to telephony devices such as telephones, fax machines, PBXs, and PSTN CO switches. These devices may use any of several types of signaling interfaces to generate information about on-hook status, ringing, and line seizure. Traditional two wired FXS and FXO voice ports typically use so called Loop-Start and Ground-Start supervisory signaling. I am going to explain how these types signaling work in the in the next few paragraphs.

Understanding Cisco Voice Gateways - Part 2. Analog Voice Ports

Today we are going to continue our conversation about Cisco Voice Gateways. In the beginning we defined what the voice gateways are, and now it is time to see how we can connect our VoIP infrastructure to traditional analog lines or devices. Yes, it is 2022, however the analog connections are still implemented. That's why you have to know how to use analog voice ports on your voice gateways. 

Understanding Cisco Voice Gateways - Part 1

The previous topic about Caller ID issues on Cisco FXO ports was of interest to many readers, and that's why I decided to write series of posts about Cisco Voice Gateways for beginners. I see in our classes that the Voice Gateways are always a kind of a "dark horse" to our students, especially when we talk about traditional telephony interfaces, so let's talk about these devices in more detail. 

SIP Early Offer vs Delayed Offer

The most visited page in my blog is CUCM SIP Trunk to ITSP connection. From time to time my readers and students ask me to explain what the difference between the Early Offer and Delayed Offer in the SIP signaling is. Let's say your ITSP want you to use SIP signaling with Early Offer in the SIP Trunk. How can you be sure, that your SIP trunk really works in Early Offer mode?

Dropping Conference in CUCME When Initiator Disconnects

Hello all!

This post is a response to a question from a student of my recent CVOICE course. The question was as follows - how to drop a hardware Conference  in CUCME when initiator of the Conference is leaving the session.

The solution is easy. In ephone or ephone-template configuration just add a command conference drop-mode. Its syntax is:

conference drop-mode [creator | local]

Parameter creator means Conference is stopped when initiator leaves it. Parameter local says Conference is stopped when the last internal CUCME's phone disconnects from the session (ie prevents a situation where the conference are used by external subscribers only).

An example of configuration is here:

HQ-1(config)# ephone 1
HQ-1(config-ephone)# conference drop-mode creator

Wish all of you a nice day!

Presence for Сall Manager Express

Hi folks,

Today we are talking about how to set up Presence feature on the CUCME (Call Manager Express). Presence allows a user (watcher) to monitor the real-time status of another user at a directory number or SIP URI from the device of the watcher. Before making a call, one can visually see whether the other party is busy or whether it is free. Viewing the status of the DN can be configured for speed-dial buttons (Speed ​​Dials) or for call lists (Placed Calls, Missed Calls, Personal and Corporate Directories). Moreover, you can also view subsriber's status of the remote PBX. It is possible if you have a trunk with SIP signaling between those PBXs.

Examples of the simplest CUCME configuration for beginners

Good morning!

For those who are taking their first steps in the world of VoIP and learning how to configure Call Manager Express (CUCME), I think the following link will be helpful. The document provides examples of the simplest configuration of SCCP and SIP phones for registration on CME:

http://www.i-1.nl/blog/wp-content/uploads/CUCME-cheatsheet-1.0.pdf

As you can see, everything is very simple :)

О первичной интеграции CUE и CUCME. Часть 2 - Работа с CUE Initialization Wizard

Здравствуйте! :)

Всем желаю хорошего дня! :) Продолжаем наш разговор о первичной интеграции CUE и CUCME. В первой части мы рассмотрели операции, необходимые для первичной настройки CUCME. Теперь же познакомимся с начальной настройкой CUE, и для этого воспользуемся мастером первичных настроек, так называемым Initialization Wizard.

О первичной интеграции CUE и CUCME. Часть 1 - Настройка CUCME

Доброе утро, коллеги!

На днях занимался настройкой продукта Cisco Unity Express (CUE). Это модуль голосовой почты, который применяется совместно с Call Manager Express (CUCME) в решениях для малых и средних компаний. Он устанавливается в виде дополнительного модуля в маршрутизаторы Cisco. В некоторых продуктах (UC500) модуль голосовой почты является встроенным. Хотелось бы описать процедуру первичных настроек, которые необходимо сделать для интеграции CUE и CUCME. Говоря более просто - какие настройки необходимо сделать, чтобы CUE и CUCME установили между собой взаимодействие.

Динамическая маршрутизация телефонных вызовов с помощью SAF / CCD, часть 2 - Настройка

Доброго времени суток!

Сегодня мы продолжим разговор, начатый нами ранее - рассмотрим настройку устройств, использующих технологию SAF / CCD. Снова передаю слово Александру Левичеву:

" Теперь научимся конфигурировать устройства, работающие в сети SAF. Для начала сконфигурируем форвардеры для установления соседства друг с другом:

Динамическая маршрутизация телефонных звонков с помощью SAF / CCD, часть 1

Здравствуйте, коллеги!

В прошлом посте я представил вам своего ученика - Александра Левичева. Теперь же хочу опубликовать материал, который подготовил для вас Александр. Он расскажет о новой технологии, появившейся в 8м релизе CUCM и CME - о сети SAF, с помощью которой можно передавать телефонные маршруты между двумя IP АТС динамически. Материал опубликуем в двух частях: первая будет посвящена обзору SAF / ССD, во второй Вы познакомитесь с настройками устройств SAF-сети.

Итак, передаю слово Александру. :)

E1 Link Clocking on Cisco Voice Gateways - How to Avoid "Slips"

Good morning! :)

Recently, at one of the courses, my students asked me the question - how to get rid of such a phenomenon as "slips" on the E1 links when connecting a Cisco gateway to another PBX or to PSTN? I would like to suggest a solution for everyone who faced a similar problem.

What is a "slip"? This is the term used for one of the errors related to the wrong clocking  (desynchronization) of the E1 link. For the correct operation of the E1 stream, its exact clocking with the opposite side is necessary in order to know at what points in time the samples of certain timeslots are transmitted. If the clocking is wrong, the PBX can mistakenly take the sample bits of neighboring timeslots for the sample bits of this time slot, i.e., in other words, the PBX does not know at what point in time the sample bits of this timeslot are transmitted.

How to register SIP third-party phones on Cisco Call Manager Express (CUCME)

Good day! :)

After another business trip to the branch, I can’t sleep in the morning :( - a 3-hour time difference affects, and I decided not to waste time and write a new post. It will tell you how to register a third-party SIP phone on Call Manager Express (hereinafter referred to as CUCME As you know, at present, many manufacturers produce phones that operate using the SIP protocol, and therefore you can find a wide variety of them: both software and hardware.

Hardware Media Resources on CUCME

Hello again, my dear colleagues! :)

Finally I got some time for another blog post. As always, there was a lot of work, despite the summer period, there was a business trip to our branch in Almaty, where I delivered my traditional Cisco voice courses. And, of course, there was a long-awaited vacation. :)

The reason for writing today's message was my joint work with one of my students - Adonis Troitsky from Almaty. Recently, I assisted him in solving a problem with the registration of hardware media resources (conference bridge and transcoder) on CUCME 8.0. The Cisco Authorized Courses go into some detail about how media resources work with the "server" Cisco Call Manager (CUCM), but they don't cover how to use it with CUCME (Cisco Unified Communication Manager Express). Let's compensate the vendor's omission and cover this topic in more detail.