Questions tagged [voip]

For questions about Voice over Internet Protocol (VoIP) which encompasses various technologies (methods, functions, and encapsulations) for encoding and delivering audio on a network using IP.

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9 views

Silent VOIP call in one direction [closed]

I have been working on a problem with some VOIP phones in one of my branches at work, Phone A - Yealink T23P in my test lab - number/username ends 2022 Phone B - Yealink T46G in the branch - number/...
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1answer
23 views

How to connect 2 SIP trunks to a PBX device which only has 1 SIP trunk port?

I stumbled upon a bit of an issue regarding SIP trunk here. In short, I am doing a PBX project for a company & this company leased 2 SIP trunks from the local telephone service provider. The ...
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1answer
224 views

How to set up VoIP inside local network without a VoIP server?

I have a task to set up VoIP inside a small network (~20 Cisco IP Phone 303). Only for calls inside the local network. I have no previous experience with VoIP and I want to do everything in the most ...
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4answers
374 views

Cisco Vlan block access

So I have 2 core switches and 1 access switch, I have the vlans 1, 10, 20, 30 and 100. Vlan 10 is voip and what I would like to do is stop anyone on the other vlans from being able to see that subnet, ...
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1answer
4k views

Why and when do we use digit '9' before making an outbound call?

Also explain when do we use this feature (Please explain for both VOIP & Traditional telephony system)? Why we use this feature? what problems shall we face if we don't use '9' before making ...
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2answers
8k views

Do i need to configure VLANS on my router/firewall or just the switch?

I finally took time to map my entire shitty network to understand exactly what the guy before me did, and i must admit i'm a little bit surprised even if i'm not a network expert... Just take a look ...
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2answers
52 views

Cisco 3750 - configure to mimic multi location scenario

Good morning. For starters, I am less than a noob with cisco products. I can access, so basic trunking for our nec phone systems, etc. I have a 3750 that I'd like to configure to mimic a multi ...
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2answers
1k views

Whats the difference between VOICE VLAN and ACCESS VLAN

Can someone please tell me the difference in Layman's termsfor these 2 configurations? interface FastEthernet0/1 description PHONES switchport mode access **switchport voice vlan 51** spanning-...
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11 views

Can I configure Voice VLAN on Huawei switches in access port mode?

The official documentation describes hybrid mode, but I see that in access mode, commands for configuring Voice VLAN are also available. Can I still configure Voice VLAN in access mode, has anyone ...
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19 views

Don't play music on hold for conferences

At my workplace we use Cisco video phones, CUCM, VCS, and MCU for conferences. Recently we have had some embarrassing situations where someone puts the conference on hold and everyone has to talk over ...
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1answer
113 views

Firmware of Cisco Phone

i want to configure IP phone Cisco DX650 with Sip.Anyone have idea about it how i can upload firmware of sip feature
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1answer
355 views

Is TCP slow start supposed to be enabled for VoIP SIP?

TCP slow start mechanism generally is pretty useful in most cases. But it is not so good and reasonable for short-lived TCP connections. Hence the question: Should TCP slow start be used with SIP-over-...
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1answer
110 views

Cisco Unity Connection guest, ESXi host, IP phones, vlan, subnet, ip addresses, qos

I have setup: VLAN 1 and subnet 192.168.1.0/24 for data VLAN 100 and subnet 192.168.100.0/24 for voice IP phones get their IP via DHCP on the subnet 192.168.100.0/24 all other IP devices get their IP ...
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1answer
63 views

ISP Failover On A Converged Network

We have our fiber provider as our primary ISP. We have Comcast as our secondary ISP and our VoIP provider. We can setup the failover between the two ISPs. We also have 19 VoIP phones that are on a ...
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1answer
532 views

Using DTMF signals of a VoIP gateway when interacting with an analog ministation (PBX)

There is such a configuration: Internet ===> [WAN port] Grandstream HT812 with hosted PBX users [FXS ports] ===> analog ministation Panasonic ===> analog telephone sets Situation: When a caller ...
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2answers
63 views

How does UDP provide continuous sound in VOIP even though segments are discrete?

I would like to know how does UDP achieve continuity in VOIP or in any streaming service.
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2k views

Why does yealink ip phone is not getting ip address from voice vlan?

I have configured separate vlan for voip and connected interface to it (as shown below). But the phone is not getting ip address automatically. switch- cisco 2960-x phone- yealink I had tried: (on ...
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4answers
2k views

Can I run two separate internet connections over one Cat5e cable

I have two ISP's coming into the building. One is a T1 that is going to be used for VOIP phones. The second is high speed internet connection going to be used for internet. Each office has one cat5e ...
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3answers
10k views

How is it possible to run VoIP on CAT3. Do you not need CAT5 for the voice data?

So I never knew this till today but I thought you needed CAT5 for VoIP but this business is running VoIP on CAT3. Don't you need the extra wires for the voice, data and power?
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1answer
127 views

Replacing IP address of connections from AWS towards SIP

We have installed a PBX on AWS and connected it to our on-prem Router via VPN. My on-prem router is connected to the SIP provider via a physical connection with another on-prem MUX device (device ...
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1answer
71 views

VoIP, IPsec configuration

I have a topology in GNS3 with an IPsec VPN tunnel between C1 and C2 (https://imgur.com/dnNkssU). In clients networks i am configured a CME and a Softphone. When i make a call the quality is very bad. ...
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1answer
4k views

Cisco ASA SIP/RTP inspection question

I have following scenario: [VoIP phone]--------[ASA 5550]----------[SIP Server] VoIP phone: 10.0.0.10 SIP server: Public Address Question: In above scenario do i need to specify or open RTP ...
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1answer
593 views

qos inside vpn, possible or not ? I read yes and no

I am wondering if possible to do QOS (or similar action) inside vpn tunnel to a cloud server. the goal is to reserved bandwith for voip traffic. I read that you can with GRE and other people said, ...
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0answers
1k views

Cisco 871, NAT, port formwarding and VOIP configuration - phone speaker buzz

I'm new to all Cisco stuff and I need to configure nettalk VOIP. I have Cisco 871 device with two ISP - one via PPP (public IP 666.666.666.666) and one via eth (public IP 999.999.999.999). Main ISP ...
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1answer
684 views

How does “dual-line” feature work on Cisco/Avaya IP phones for VOIP?

For below CME configuration which I configured on UC500 where ephones are not configured with dual-line feature and in button command separator 'c'(call waiting) is used. CME_VOICE(config)#ephone-dn ...
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1answer
2k views

Outgoing call routing issue Avaya IP Office PBX

I have an Avaya IP Office PBX phone system. There is a T1 coming in for the trunk. There were 6 numbers associated tot he trunk. 4 of the numbers were taken off by Telco provider and converted to ...
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1answer
381 views

VLAN VoIP and LAN configuration over multiple switches

Some background: I currently have: Switch A Main 48 port 1Gbps (DLink) Switch B 10Gbps Backbackbone (DLink) Switch C 24 port 1Gbps (DLink) Telephone Switch 1-24 port phone switch connected to a ...
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1answer
699 views

HP V1910 ProCurve Voice VLAN auto mode possible with LLDP and no OUI mask?

On a ProCurve V1910 I have configured Voice VLAN as follows in network settings using the Web UI: LLDP -> Global Setup -> LLDP Enable -> Set Enable VLAN -> Modify Port -> Select ports -> Set Link ...
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1answer
67 views

VoIP Provider and Phone Number Routing Questions

I am fairly familiar with VoIP and I have my own VoIP PBX, and my provider is Twilio (for Voice) and CallCentric (for Fax). But How do providers like Twilio work exactly? More specifically: How do ...
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2answers
694 views

VLAN Tags Being Different for a VoIP Phone vs. the Host Daisy-Chained to it?

I've recently began working for a VoIP Provider and I am constantly seeing VoIP Phones pulling different VLANs than the Host that is connected to it i.e. daisy-chained. When I've tried to look more ...
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1answer
73 views

Landline phone on VOIP network without an adapter

Today someone asked me if he can make calls using a regular landline phone connected to a VOIP network without using a VOIP adapter, just by using an Ethernet to Telephone line adapter, at his work he ...
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2answers
401 views

VLANs isolating networks (VoIP/Wi-Fi)

I have to set up our network in our new office. I'm no networking expert (developer), but I need some input and advice here for some things I wonder about. I have purchased the following: 2 x Cisco ...
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53 views

TCL Tool Command Language tclsh - Script for Cisco SPA508G Phone Sidecar Auto-attendant

Using Cisco SPA508G phones with SPA500S Sidecar Console. In the Cisco UI Sidecar programming is the script: fnc=blf+sd+cp;sub=108@$PROXY;nme=Steve J. I need both sub=108@$PROXY and sub=408@$PROXY ...
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199 views

Changing DSCP values in a Cisco Switch [closed]

We have an endpoint which cannot tag outgoing RTP packets as 46 (EF).... Currently they happily churn out as 0 Can the Cisco switch it is entering, recognise it's RTP traffic and then change the ...
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1answer
307 views

Is an SBC sufficient and can it NAT

We have a gateway which faces out to our VoIP SP. As we get more users we need some security in front of it. Currently our gateway terminates directly to the SP. We would like to put a SBC in front ...
4
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1answer
15k views

Converting PCAP to WAV

How would I go about converting a RTP stream from a pcap file to wav format with a command-line tool such as sox?
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2answers
59 views

Advice on potentially needed subnet expansions

I work for a non-profit with some slightly more antiquated hardware. We have 3 locations, about 700 devices across them. Right now our locations are set up as: Location 1 (Main) - /23 with a DHCP ...
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0answers
417 views

Cisco phone display name change

I am trying to change name on cisco ip phone 7942. I changed the name in directory number configuration and in phone configuration of phone on CUCM. I did reset of phone too. But still showing the old ...
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0answers
51 views

QOS - the need for it and verifying it

Just some straightforward questions, hope gurus here can shed some light 1) show int - output queue -> this is the hardware queue (tx-ring) or this is the software queue ? if I see drop, this means ...
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1answer
345 views

ESI PBX LAN-only VoIP phone forwarding thru IPSec tunnel - remote router sees packets but not phone, doesn't forward

Okay, so we have an older X-Class ESI PBX system, an ESI IVX 128x FSIII [see below for link]. We have an LNC card installed in it, which allows for the use of up to 12 LAN-only VoIP phones. We have an ...
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3answers
2k views

Is QoS an issue for VOIP calls over the Internet? If not, why not?

I'm trying to decide whether I should buy SIP trunks from my ISP or a 3rd-party. As I understand it, it's important to maintain QoS on an internal network (i.e. prioritize VOIP traffic). Is this not ...
4
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2answers
1k views

IP Phones causing printing issue

Background We have Mitel IP phones. The phones use dhcp option 125 to get configuration information, and this tells them to use 802.11q tags for vlan id #5, with address range 192.168.16.0/24. Our ...
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1answer
280 views

VOIP timeout behind Cisco ASA after Duplicate ACK and Retransmissions

We have a RingCentral Polycom VVX series VOIP phone behind a Cisco ASA 5506 that will provision, work for about five minutes, go off-line for 20 minutes then reconnect and continue to work unless ...
4
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1answer
245 views

What Is Session Border Controller [closed]

What is Session Border Controller(SBC). And What is the Advantages of SBC. How Does It Works?
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1answer
2k views

1-1 NAT on a SonicWall with a DMZ

A new PBX is being installed at one of our clients today, and they have requested that we give them one of our unused public IP addresses(Comcast is the ISP, have a block of IPs) for use with the PBX. ...
3
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0answers
70 views

Configure C1861 for SIP to FXS port [closed]

I found a C1861 ISR router and I would like to play with it a learn some telephony. I signed up for a VOIP service so I have SIP credentials. Is there a simple walkthrough anywhere to set up the SIP ...
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1answer
861 views

Phone and PC network sharing one wifi bridge

We have a Cisco router from our T-mobile provider, two subnets on two ethernet ports: one subnet for PC data network, one subnet for IP phone network. The subnets have different IP addressing. As per ...
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1answer
304 views

QoS implementation for VoIP network

We are in VoIP business and running RTP/SIP traffic 80% in our network we have other servers also like www and monitoring and operation, our network is very flat and simple also we have very basic ...
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1answer
858 views

Fortigate 90D SD-WAN: VPN and VoIP

i am contemplating the idea of switching our current FG 80D to a 90D and implement SD-WAN using our current 100Mbit fiber circuit (main) and the 4G LTE (cradlepoint) for internet backup. Our current ...
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1answer
262 views

Configure switch in GNS3

Is there any way to configure a switch in GNS3?