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…
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…
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…
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…
This morning I participated in a discussion on Cisco Community about a problem with Caller ID on FXO port. And this discussion reminded me my recent experience with a similar problem, which one of my customer faced in his Cisco PSTN voice gateway. It was new configuration for a voice gateway in a small branch…
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…
Recently, one of our students encountered a problem when connecting his CUCM to a telephony provider (ITSP) via a SIP trunk. Between the CUCM and the ITSP, a CUBE gateway was installed, as expected. The problem was the following: when making an outgoing call to the ITSP, CUBE sent a SIP INVITE, however, the provider…
Good day, Many of my readers and students are very interested in the topic of how to connect their CUCM to IP telephony service provider via SIP-trunk. This topic is very relevant, as more and more providers offer SIP services and connections, in addition to traditional E1 or BRI lines. This post will discuss the basic settings…
Good afternoon, A few days ago, one of the readers of my blog, Alexander Bakulin, asked me what command is used to synchronize E1 links on Huawei voice gateways. I could not answer this question, because I do not work with the Chinese devices, and advised Alexander to google. He found the answer to it…
Good afternoon, Today I happened to be convinced once again in practice how it is important to understand the principles of call routing in Cisco voice gateways. One of my students had the following problem: he was performing a new installation of CUCM at a customer side and then connecting the CUCM to the PSTM…
Hello, Last week, I helped two followers of my blog to solve a problem with an H323 connection between a Cisco Voice Gateway and a Huawei Voice Gateway. The topologies of both networks were as follows: PBX1 (E1) -> E1 Cisco -> H323 -> Huawei E1 -> (E1) PBX2 The problem was this one: when…
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.…
Hi all! Today we will consider one of the options for connecting Cisco Unified Communications Manager (hereinafter referred to as CUCM) to the Public Switch Telephony Network (or PSTN). This is usually done with the voice gateways. A voice gateway is a device that combines two different telephone networks together, for example, when connecting an…