Voice over Internet Protocol (Voice over IP, VoIP) is one of a family of internet technologies, communication protocols, and transmission technologies for delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.

learn more… | top users | synonyms

0
votes
2answers
72 views

Asterisk, GSM-FXO gateway example of usage

Can anyone explain where to use GSM-FXO gateway. I understand where to use GSM-FXS - for example to connect analogue telephone to gsm gateway. But do we use GSM-FXO to connect to two telephone ...
2
votes
0answers
55 views

How to set Mitel 5224 ringer volume in configuration?

We have several Mitel 5224 SIP phones, but can't seem to find out to make the ringer volume setting persist after it reboots. Can the ringer volume can be set somewhere in the XML configuration file?
1
vote
2answers
334 views

Setting up VOIP system on separate VLAN / Server on default VLAN

First off, I am not a network engineer so apologies if I get terminology messed up, i realize accuracy is important here. Currently, we have a small(ish) network with around 40 devices and 20 IP ...
1
vote
0answers
297 views

Cisco SPA504G phone CDP/LLDP issue

Good morning everyone, Just recently signed up for the site because I'm looking for some help with an issue that's been plaguing me for about a week now. I hope I'm posting in the right place. If ...
1
vote
1answer
67 views

Which one VoIP SIP audio codec should I choose to high quality calls?

The quality of VoIP calls depends on the codec used for the transmission and on the bandwidth of Internet connection. I want to use best optimized codec for my Internet connection. I have to select ...
1
vote
1answer
218 views

Asterisk ignoring sip_domain part of URI

I am using Asterisk version 11.5. My problem is the following: I literally cannot make any outbound call. That's because, whatever I dial in any client, the sip_domain part gets ignored, it is ...
0
votes
2answers
669 views

Limiting Bandwidth per port Cisco router

Let's say a businessses purchases a sufficently fast internet connection (such as 60Mbps cable connection) and VOIP quality is pretty good for the most part. The only thing I would be worried about ...
1
vote
3answers
410 views

Asterisk and SIP trunking, is this configuration possible?

I am new to asterisk and before I dive in, I just want to make sure that what I plan to do is possible/correct. My office will run an asterisk server and have both local and remote extensions. We ...
-5
votes
2answers
306 views

Make own dial-up ISP using broadband connection [closed]

So, I see no reason why this wouldn't be possible. I have a Linux server (a Raspberry Pi to be exact) connected via Ethernet to a broadband ISP. I want to be able to dial a number, have it go ...
1
vote
1answer
1k views

VoIP Network Components: Difference between Signaling Gateway, Media Gateway, Softswitch [closed]

In my degree course of Software Engineering we had a lecture in Computer Networking about VoIP and the Session Initiation Protocol (SIP). There were many terms brought up for some network components ...
1
vote
2answers
162 views

What determines the length of RTP packets?

I have established a SIP session between two clients. I observed the RTP trace between them on wireshark. The 'length' column has a value of 172 for the RTP packets that flow from Client 1 to Client 2 ...
3
votes
2answers
5k views

Factory Reset Cisco SPA504G without admin password

I've been trying to factory reset some SPA500 phones, specifically the 504G but the old provider has locked out everything. I need to reset about 50 phones for use with a new service. I've man in the ...
0
votes
1answer
77 views

Limit Cisco IP phone to only one subnet ranges DHCP

We run stretched layer 2 and we have the e911 service setup to correspond for each location. We run different sub-nets for each location as well. I'm wondering if there is a way to limit a users ...
1
vote
1answer
314 views

What is the best option for SIP service redundancy?

From your practical experience, what is the best option for SIP service redundancy? a) one SRV record pointing to a hostname which has two A records b) two SRV records pointing to two different ...
0
votes
1answer
83 views

Is there a Lync equivalent of Avaya's Telecommuter Mode?

In Avaya Telecommuter mode, the Avaya IP Office has an option to route the voice call to an Avaya hard/soft phone to a traditional phone in the PSTN. While the TCP traffic for call handling goes to ...
0
votes
1answer
46 views

How to use fax with my VoIP

Well the site seems to be Hide Park for networking experts. To be honest I am not any expert at all. I followed my friend have recently got a business plan (for my new business) from Axvoice because ...
0
votes
1answer
255 views

Asterisk / Voip phone redirects to last called number

I experience a very strange problem with our PBX (Asterisk 1.8, FreePBX, Grandstream GXP1200 phones) If I call an internal number (1020 in this case) the asterisk server redirects me to the last ...
2
votes
5answers
226 views

VOIP Power outage strategy

In the past 2 years, we have had 4 instances where we have been without power for a period of 4-6 hours - due to construction crews cutting power lines, car accidents involving downed power lines, ...
0
votes
1answer
132 views

3com VCX - how to get a dump of outgoing phone calls

I am looking (hoping) for a way to dump a list of all outgoing calls from the VCX for a time period? Possible via the web interface, or via the ssh interface. For example, we need the date (time ...
5
votes
2answers
100 views

Trans-atlantic VOIP

We're a Canadian business on the east coast and will soon be opening up a new call centre in Australia. This new call centre will be handling our graveyard shift and will be overlapping with the ...
1
vote
2answers
364 views

VoIP client permamently losing connection after ISP IP reset

I have a SIP client device connected to my ADSL router, so it is behind a symmetric NAT. My ISP resets the client's IP every 24 hours, it looks like this in the router log: Mar 26 12:36:56 daemon ...
0
votes
2answers
160 views

DHCP and ip assignment with VoiP

We just added a Cisco SPA122 ATA with Router to our network, it will be used for our paging system (an amplifier/speakers). We are having a hard time getting it work. Well until we found out the ip ...
1
vote
1answer
955 views

Poor audio quality during RDP with thin client from Windows Multipoint Server 2012

we have problems with audio quality from Windows Multipoint Server 2012 during RDP sessions, we are using Thin Clients for the Remote Desktop the display is good but the audio quality is bad, there ...
0
votes
1answer
539 views

Is there a traceroute command for VXWorks? Specifically a Shoretel Phone?

I can't seem to find if there is a traceroute command for VXworks online or specifically with a Shoretel phone. Once I telnet into the phone, I would like the ability to see whether packets from my ...
0
votes
1answer
207 views

Custom ENUM/NAPTR DNS Server

I need to configure custom DNS server to handle ENUM requests for VoIP calls I have custom built DNS server in Java that handles ENUM requests for my company's VoIP services. ENUM is used to ...
0
votes
1answer
131 views

Variable to store Asterisk extension dialed by user

I am using Asterisk for voice calling. I am using below context If user call back- [from-pstn] exten => _X.,1,Playback(demo-thanks) suppose my number is 74900 on which user can call back. ...
1
vote
0answers
333 views

UDP Range Nat Translation port forwarding RPT Traffic to inside host PBX Cisco ASA 5505 8.2a

I have an Asterisk based PBX that I'm providing VoIP services with, My gateway is a Cisco ASA 5505 running 8.2 and I only have one public IP Available along with other services I provide with that IP. ...
16
votes
4answers
337 views

What alternatives do I have for telephony if my LEC says the Central Office has an issue?

In our New York office we've been waiting for almost a month for Verizon Business to repair a problem at our local CO. They keep saying that the damage from Hurricane Sandy was so extensive that they ...
5
votes
2answers
423 views

Is it possible for Wireshark to drop packets purposely?

I would like to test something like VoIP. I would like to test with some "artificial packet loss". Is Wireshark able to do this? Or is there any good solutions?
1
vote
1answer
637 views

VOIP phones stop working when spanning-tree (STP) enabled on switch

I have a few different types of managed switches, including mostly 3com Super Stacks, Baselines (for example, one specifically is a 3com baseline pwr-plus 2928). Most of them are configured with two ...
0
votes
1answer
2k views

How to route/forward/connect incoming SIP call through other SIP provider to a phone number?

I have 2 VOIP SIP accounts. One is for a landline (incoming). The other should be purely outgoing and allows for calls to my mobile phone. Basically I want to connect the landline to my mobile phone. ...
4
votes
2answers
888 views

What would cause a PBX or SIP phone to not register on the network when using Netgear Switches?

We have 3 different types of switches in our network. All of our IP Phones are running on HP 2520-24 PoE switches. Our primary backbone is "supposed to be" running on Netgear GS748T switches. ...
2
votes
0answers
3k views

Setting Shoretel phone time correctly with dhcpd

Our Shoretel 230 phones are not picking up time service correctly and thus, the time on the display is wrong. When I go to the diagnostics of the phone, they are using a wrong time server (old). Here ...
0
votes
1answer
87 views

Which handsets work with IP DECT base?

My workplace uses an Ascom IP DECT base station (IPBS1), and Ascom handsets as well. We're looking to replace some broken handsets; the ones by Ascom, however, are rather expensive, and we're not ...
1
vote
1answer
459 views

Asterisk Connection not working

I have installed Asterisk on VirtualBox by following the steps from here. Everything went ok until I got to navigate to an IP to configure Asterisk using FreePBX: 10.0.2.15 (Shouldn't be something ...
0
votes
1answer
854 views

asterisk peer with SIP provider through proxy

I'm trying to make a asterisk server connect to a SIP provider (which offers PSTN origination and termination). I've been reading the great Definitive Guide, but it doesn't seem to cover the case ...
1
vote
1answer
966 views

Accept calls on external cell phones - FreePBX Distro

We installed FreePBX distro last week and configured it so that when someone calls in, it goes to all the phones so someone here can answer the call. After trying all the internal extensions, it ...
1
vote
1answer
377 views

How to establish SIP connection, when SIP-proxy is required?

I have Asterisk/1.8.13.1 Asterisk GUI-version : SVN--r Yes, quite old one, but I can not update it since this is installed on my Synology NAS. NAS is connected to internet thru router Asus RT-N16. ...
0
votes
1answer
416 views

Asterisk dialplan context and label clarifications

I have been learning Asterisk dial plan for the past week.I have written down a simple IVR system with two levels of menu and an exit option.I have used concepts from different tutorials on the ...
2
votes
1answer
492 views

Configuration of a Cisco IP Phone 7916 and 7975g

Hi everyone, I would appreciate some help configuring my Cisco IP Phone 7975. In fact the phone works well with the SIP firmware (version SIP75.8-4-1ES2) and an Asterisk Server. Now I would like to ...
1
vote
1answer
111 views

SIP me@domain.com vs (123) 456-7890

I'm trying to understand SIP, and one thing that keeps confusing me is phone numbers and dialing plans vs SIP URI's like me@domain.com. What is the difference? How do they coexist/work together? For ...
0
votes
1answer
314 views

Cisco CME to CME - phone rings but silence on pickup

I have two Cisco 2901 routers with CME, DSP module and built-in poe switches. They are both linked together via Ethernet. I have 2 phones connected to each router. Making calls between 2 phones on ...
14
votes
2answers
1k views

Can anybody explain why to use Asterisk PBX rather than standard PBX from Matrix or Siemens [closed]

Can anybody explain why open-source Asterisk is favourable in comparison with a traditional PBX system from a vendor such as NEC/Syntel/Matrix or Siemens.
2
votes
1answer
526 views

Elastix and two ISDN lines

Since I am not an expert on communications, I will describe everything from the user perspective. We had a PBX with elastix embedded and two ISDN cards in it (we have two isdn lines). The mobo of the ...
1
vote
0answers
402 views

Cisco VoIP stuck as Unregistered?

Question: Why is one VoIP stuck as Unregistered? Background: We have a Cisco UC540 Small Business switch/router/voip combo. This phone was working until I powered everything down to install a ...
0
votes
1answer
294 views

ShoreTel P2V Audio Issue

I recently P2V'd my ShoreTel server. After doing so everything seems fine. No errors anywhere, and everything looks good in Director except for a licensing issue since the mac address changed. ...
1
vote
1answer
113 views

Turn old rack server into a telephone server

I have an old server lying around and I am thinking of using it as an internal telephone server. Its main use would be to set up a 1 to 1 telephone system that could be used internally to connect to ...
1
vote
3answers
859 views

Elastix and extensions.conf

My VOIP provider required me to add this into /etc/asterisk/extensions.conf: exten => h,1,Hangup exten => _00X.,1, Answer exten => _00X.,n, Set(CALLERID(num)=96354205144239) ; exten => ...
0
votes
2answers
869 views

Skype Connect and Elastix for incoming and outgoing calls

I ordered Skype Connect, And i want to integrate skype connect with my Elastix server to handle incoming and outgoing calls. I created new SIP Trunk through GUI with the following info : ...
0
votes
1answer
892 views

Elastix call-center with computer telephony crm integration

The title isn't explanatory enough but I can't explain it better. I want to setup a call-center using elastix which would have the following feature: Suppose bob(client) calls the center and ...