Jordan: SIP providers and connecting a number to your PBX
We do not issue phone numbers: the venue buys a Jordanian number from a carrier and connects it to its own PBX as a trunk. Everything that is the same in every country — trunk modes, form fields, network requirements and connectivity checks — is covered in the overview “Connecting a provider's number to your PBX”. This page covers only the Jordanian part: where to get a number, what to enter in the admin panel and what people trip over in this country.
The data was collected on 9 September 2026 from the carriers' own websites, the numbering registry of the regulator TRC and the documentation of international providers; links are in the “Sources” section.
In brief#
- Trunks for your own PBX are sold openly in Jordan, and it is the carrier who needs the licence, not the venue. SIP trunking is listed in the enterprise catalogues of Orange Jordan, Zain, Umniah, Mada and Viacloud; the venue buys the service as an ordinary corporate customer under a contract with a local legal entity.
- No Jordanian carrier publishes its trunk parameters. Host, port, transport, authentication mode and codecs arrive in the provisioning sheet from the engineer. That is why the tables below tell you what to enter and where to get it, not ready-made values: “typical” values are useless here.
- There is one question to ask the carrier, and ask it before signing: “do you deliver the trunk over the public internet to our static IP, and how do you authenticate it — REGISTER or an IP allowlist?” An answer of “only over our own circuit” means the setup with a cloud PBX will not happen.
- Two of the five answer that question with “no” on their own websites. Umniah states plainly that its services run “through privately managed IP networks rather than public Internet”, and Mada draws the topology as “your IP PBX → Border Element (its own firewall on your premises) → the Mada network”. Neither scheme accepts a cloud PBX.
- A landline number fits our PBX perfectly, a mobile one does not. The subscriber part of a landline number is exactly 7 digits — the same length the line matches on. A mobile number has 8 digits after
07, and the first of them is left out of the match:079 1234567and078 1234567become one line. Zain's “unified number” is exactly that kind of079Xnumber. - Mobile number portability does not exist in the country yet — TRC's tender documents put the launch at the end of March 2027. A number taken “for now” will not move to another carrier later.
Numbers in Jordan#
The country code is +962, the national prefix is a leading 0 and the international prefix is 00. From abroad the number is dialled without the leading zero: +962 6 5XX XXXX.
| Number type | National format | In E.164 | Where it is used |
|---|---|---|---|
| Landline, Amman | 06 XXX XXXX |
+962 6 XXX XXXX |
Amman and suburbs |
| Landline, north | 02 XXX XXXX |
+962 2 XXX XXXX |
Irbid, Jerash, Ajloun, Mafraq |
| Landline, south | 03 XXX XXXX |
+962 3 XXX XXXX |
Aqaba, Ma'an, Tafilah, Karak |
| Landline, centre | 05 XXX XXXX |
+962 5 XXX XXXX |
Zarqa, Madaba, Balqa |
| Mobile | 07X XXX XXXX |
+962 7X XXX XXXX |
nationwide |
| Non-geographic fixed | 08 7XX XXXX |
+962 8 7XX XXXX |
“new generation” carriers |
| Toll-free for the caller | 0800 … |
+962 800 … |
Toll Free service from carriers |
- The subscriber part of a landline number is 7 digits, and the area code is a single digit after the zero. That is exactly the length the line in the PBX matches on, so the format of the incoming call does not matter.
- Mobile ranges by carrier (TRC numbering registry in the ITU bulletin): Orange Mobile —
70,71,72,75–79; Umniah —80,81,82,85–89; Zain —90,91,92,95–99. - The non-geographic
08 7XXrange is held by Batelco Jordan (8 720), Jordan Data Communications (8 778), Tarasol (8 770), Metrobeam (8 790), Zain (8 799) and Viacloud (8 700 0XXX). A local guest reads such a number as “not a landline” — worth keeping in mind for the signage. - No carrier publishes the form in which the number arrives in an incoming call. Be ready for any of the three: E.164 without the plus (
9626XXXXXXX), national with a leading zero (06XXXXXXX) or the bare subscriber part. On the first connection look at the SIP trace to see what the carrier actually sends, and only then create the lines. - Codecs are published by none of the Jordanian carriers — ask at provisioning time. We support G.711 a-law/u-law and G.722; a “G.729 only” trunk will not work.
- Emergency numbers (TRC's notification in the ITU bulletin): 911 — the single emergency number, 191 police, 199 civil defence, 190 road accidents, 194 traffic patrol, 112 from mobiles, 109 poison control, 110 and 111 family support lines. Our PBX does not handle emergency calls — there must always be an ordinary phone or a mobile on the shift.
Who sells a number with a SIP trunk#
| Provider | Numbers offered | Trunk for your own PBX | Mode | How to order |
|---|---|---|---|---|
| Orange Jordan (Jordan Telecom) | landlines in every area, 0800, DIDs as an add-on |
yes — “SIP Trunk”, packages of 15 / 30 / 60 channels | provided at provisioning | businesscare@orange.com, 06-5800999, 1215 |
| Zain Jordan | unified 079X, landlines, 8 799 |
yes — “PRI/SIP Line” to your corporate PBX | provided at provisioning | “Request a follow up” form on the service page |
| Viacloud Jordan | 6 559 XXXX, 8 700 0XXX |
yes — “BusinessSIP”, a SIP link to your office PBX | provided at activation | Amman office, Al Madinah Al Munawarah St |
| Umniah | landlines, mobiles | yes — “Fixed Corporate Voice (SIP/PRI)”, over a managed IP network, not the internet | provided at provisioning | +962 7880 01333 |
| Mada Jordan | landlines 2 691, 3 241, 5 301, 6 400, 6 401 |
yes — but through a Border Element on your premises | provided at provisioning | Mada enterprise sales |
| Tarasol Telecom | 6 300, 8 770 |
unknown — the website is down | — | no contact in public sources |
| Metrobeam Wireless | 6 250, 8 790 |
unknown — no public materials | — | via the TRC registry |
| Damamax | no ranges in the TRC registry | no — no voice products offered | — | as a connectivity provider: +962 6 5777740 |
| Twilio · didlogic | +962 800; didlogic also national +962 |
yes | per their own rules | online, see “International providers” |
| Plivo · DIDWW · Telnyx · CommPeak | no Jordanian inbound numbers confirmed | — | — | see “International providers” |
Below are cards for the three carriers whose trunk to a third-party PBX is a product in its own right, plus a review of the rest. All of them hand over parameters under contract; the full list of questions for the account manager is in “What to ask your provider”.
Orange Jordan — SIP Trunk#
The fixed-line incumbent (formerly Jordan Telecom, part of the Orange group) and the holder of the largest share of the country's geographic numbering. Its enterprise catalogue “Business Internet & Connectivity → Fixed Services” lists five products: Land Line, SIP Trunk, Toll Free, BRI and PRI. The service is described as “Orange SIP Trunk Service… allows the customer to perform all his voice calls using the Voice over Internet service through the Session Initiation Protocol (SIP)” — this is the only carrier in the country that publishes capacity and pricing.
Packages (annual contract): Basic — 15 concurrent calls, Heavy — 30 plus one discounted international zone, Premium — 60 plus two zones. Local and national minutes are advertised as unlimited. Sold on top: “Fixed 2 Mobile” bundles of 1,500 / 3,000 / 6,500 minutes, additional DID numbers and the SIP Arab / Asia / Europe / North America international zones; a minute to an international zone is JOD 0.25 at the standard rate and JOD 0.08–0.20 at the discounted one.
What to enter in the admin panel (Telephony → “Trunks and connections” → “Add provider”):
| Field | Value |
|---|---|
| SIP host | the address Orange gives you in the provisioning sheet — the trunk has no public address |
| Port | from the sheet; for SIP trunks this is usually 5060 |
| Transport | UDP or TCP, whichever the engineer names; our PBX does not support TLS for trunks |
| Registration | per the sheet: ✅ “Register with the provider (REGISTER)” or ⬜ “IP auth (no registration)” — both modes work for us |
| Username | from Orange (for trunks this is usually the pilot number) |
| Password | from Orange; not used with IP authentication |
What to set up on the provider's side: order a SIP Trunk package of the right capacity → ask for the trunk to be delivered over the public internet, not only over the Orange circuit → give the engineer the static IP of your PBX from the “Server” tab → order the DID numbers as an add-on and ask for them to be routed to the trunk → confirm the codec set and the number format in incoming calls.
Pitfalls ⚠️
- “Unlimited” has ceilings: per the tariff description, 11,000 local and national minutes and 1,000 minutes to mobiles, after which it is 3 piastres per minute. The package comes with an annual contract, so test connectivity before signing.
- No technical detail before the contract. The “Check Technical Details” link on the service page leads nowhere (checked on 9 September 2026) — Orange has no separate technical document.
- Orders are taken in limited hours: the enterprise line works Saturday to Thursday, 08:00–18:00; new customers should pick option 3 in the menu.
Source: Orange Jordan — Enterprise Fixed Services — 9 September 2026.
Zain Jordan — PRI/SIP Line#
The country's largest carrier by subscriber base. Its enterprise “Voice Solutions” section includes the PRI/SIP Line product: “Zain PRI and SIP services connects Corporate PBX with Zain's Voice Gateway, allowing businesses to carry multiple voice channels between the customer and all destinations through the Zain network”. The line comes with a unified number in the 079X format and connectivity to cloud phone systems. Orders go through the “Request a follow up” form on the service page.
What to enter in the admin panel:
| Field | Value |
|---|---|
| SIP host | the address of the Zain Voice Gateway from your contract — not published publicly |
| Port | from the provisioning sheet; expected to be 5060 |
| Transport | UDP or TCP per the sheet |
| Registration | per the sheet; for a “corporate PBX ↔ Voice Gateway” setup ⬜ “IP auth (no registration)” with an allowlist is more common |
| Username | from Zain; not used with IP authentication |
| Password | from Zain; not used with IP authentication |
What to set up on the provider's side: sign the PRI/SIP Line contract as a legal entity → give Zain the static IP of your PBX for the allowlist → confirm the format the number arrives in → order extra DIDs if the single 079X number is not enough.
Pitfalls ⚠️
- The line number is in the mobile format. The subscriber part of
079Xis longer than seven digits, so the line matches on the tail without the first digit. If you have several numbers, compare the tails by hand: matching ones will collapse into a single line. - A caller sees a mobile number, not a landline — a matter of taste for a “number on the sign”, but guests usually expect
06.
Source: Zain Jordan — Voice Solutions, PRI/SIP Line — 9 September 2026.
Viacloud — BusinessSIP#
A small carrier of a Bahraini group that also operates in Jordan: the TRC numbering registry lists “Viacloud Jordan L.L.C.” with the ranges +962 6 559 XXXX and +962 8 700 0XXX, and its office is in Amman on Al Madinah Al Munawarah St. The BusinessSIP product is described as exactly what we need: “IP based Telephony Service that can support a large number of Voice channels over a single link… our team will establish a link to your office PBX system using the SIP protocol”, a replacement for PRI/BRI, with free activation and free porting of existing numbers.
⚠️ The public service page sits on the group's corporate website and is written about Bahrain; as of 9 September 2026 the carrier has no separate Jordanian website. The Jordanian licence and numbers are confirmed by the TRC registry, but whether BusinessSIP is sold in Jordan in the same form is a question for the Amman office when you order.
What to enter in the admin panel:
| Field | Value |
|---|---|
| SIP host | the address Viacloud issues when BusinessSIP is activated |
| Port | from the activation details; expected to be 5060 |
| Transport | UDP or TCP per the carrier's details |
| Registration | per the details: REGISTER or an IP allowlist — both modes are supported |
| Username | from Viacloud |
| Password | from Viacloud |
What to set up on the provider's side: sign up for BusinessSIP as a Jordanian legal entity → ask about delivering the trunk to an external static IP → order or port 06 559… / 08 700… numbers → confirm the codecs and the number of channels on the circuit.
Pitfalls ⚠️ A small carrier — the level of support and the SLA come from the contract, not from a published policy; and a local guest reads an 08 7XX number as “not a landline”.
Source: Viacloud — Voice for Business (BusinessSIP) — 9 September 2026.
Umniah and Mada — trunks not delivered over the public internet#
Both carriers do sell a SIP trunk for a third-party PBX, but there is deliberately no “what to enter” table here: the delivery method they describe themselves does not accept a cloud PBX.
- Umniah (Batelco/Beyon group) — “Fixed Corporate Voice (SIP/PRI)”: “linking your Private Branch Exchange (PBX) with our Voice Gateway through a dedicated SIP/PRI trunk”, with channels added in a matter of days. On the same service page: “Our services are offered through privately managed IP networks rather than public Internet sites”. In other words, the default delivery model is a managed circuit to your premises, not the internet. There is exactly one thing worth asking: whether the carrier will agree to hand the trunk over to an external static IP. Service contact:
+962 7880 01333. - Mada Jordan (Al-Moakhah for Telecom) — the “الاتصال الصوتي عبر الانترنت” service (SIP Trunk in the English menu) connects your IP PBX to the Mada network, but Mada's own topology has three elements: the customer's IP PBX → a Border Element (a firewall on the customer's premises that Mada is responsible for) → the Mada network. The trunk lands on the carrier's device, not on an arbitrary address in the cloud. The English version of the service page returns a 404 — the only primary source is in Arabic.
If the venue already has a circuit from one of these carriers and the PBX sits on the premises, the setup works — but that is not our model: our PBX lives in the cloud and only accepts public UDP/TCP to a static IP.
Smaller carriers and a connectivity provider#
Tarasol, Metrobeam, Batelco Jordan, Jordan Data Communications, Damamax
- Tarasol Telecom — a Jordanian carrier from Amman with the licensed ranges
+962 6 300 XXXXand+962 8 770 0XXX–8 770 9XXX. Whether it sells a trunk to a third-party PBX is unknown: as of 9 September 2026 thetarasol.jowebsite does not respond and there is no public documentation. A carrier with a dead website is a poor candidate for a venue's production telephony. - Metrobeam Wireless Telecommunications — a wireless access carrier with the voice ranges
+962 6 250 XXXXand+962 8 790 0XXX–8 790 1XXX. No working website or service materials could be found in public sources; it is in the TRC numbering registry, but trunk sales are not confirmed. - Batelco Jordan (
6 200,8 720) and Jordan Data Communications (8 778) appear in the TRC numbering registry, but neither has a public SIP trunk page. - Damamax — a fixed access carrier holding an individual licence since 2008: fibre for homes and businesses, a data centre, connectivity. Its catalogue has no voice products and the TRC registry lists no ranges for it, so there is no number to buy here. It is relevant as a connectivity provider for the premises though: with such a provider you ask for a static IP and confirmation that SIP and RTP are not filtered. Contacts:
+962 6 5777740(customers),+962 6 5777733.
International providers with Jordanian numbers#
Jordan is not a country where a number is easily bought online from abroad. What the providers' own documents confirmed on 9 September 2026:
- Twilio — for Jordan only the toll-free
+962 800number is available, and its issuing rules are inconvenient for a Jordanian venue: the owner's address (for both individuals and companies) must be outside Jordan, a signed letter of authorisation is required, and using the number for calling cards or callback is prohibited. - didlogic — its Jordan page lists national
+962and0800numbers; check the actual availability of a specific number in your account before paying. - Plivo — only outbound termination is sold for Jordan: the price list states plainly “To receive calls (Inbound) — Not Supported”. You cannot buy an inbound number there.
- DIDWW — publishes call termination to Jordan and has no page for local Jordanian numbers.
- Telnyx and CommPeak — marketing pages for “Jordan numbers” exist, but Jordan is absent from the published country-by-country DID requirements handbook, and the pages list no parameters or requirements. Ask for written confirmation that the number exists before paying.
- Zadarma has no page for Jordanian numbers — it does not sell
+962.
Trunk parameters at international providers are standard and described in the catalogue cards in the admin panel: most use REGISTER with a username and password from your account, while Twilio and Plivo use IP authentication or a credential list.
⚠️ Beware of pages titled “SIP trunking provider in Jordan” from small resellers: they are generated from a template. One of them names China's MIIT as Jordan's regulator — facts from such pages are unusable.
Number porting#
- Mobile number portability (MNP) does not exist in Jordan yet. In TRC's tender documents for an MNP solution the launch is set for “end of March 2027”, with a five-year contract for the clearing house from the launch date. Until then you cannot change mobile carrier and keep the number.
- Fixed-line portability is not described as a separate public regime. Viacloud advertises free porting of existing numbers to itself, but that text refers to the group's Bahraini arm — confirm it separately for Jordan.
- The practical conclusion: the number is tied to the carrier. If the venue plans to migrate from an on-premises system to a cloud PBX, take the number from a carrier who agrees to deliver the trunk to a public IP in the first place — otherwise the number is lost when you switch.
- ⚠️ Changing the public address of the PBX breaks a trunk that uses IP authentication. When the dedicated machine is rebuilt, tell the carrier the new address in advance.
Rules and paperwork#
The TRC regulator, licences, contracts, blocking of VoIP apps, call recording
- The regulator is the TRC (Telecommunications Regulatory Commission) in Amman, acting under the Telecommunications Law No. 13 of 1995 as amended (including No. 8 of 2002). The TRC licenses networks and services and maintains the numbering plan.
- The licence is needed by the carrier, not by the venue. Only a TRC licence holder may sell numbers and trunks; the venue buys the service as a corporate customer, and no separate permit is required to connect its own PBX to the trunk it has bought.
- The contract goes to a local legal entity. No Jordanian carrier has a public “buy a trunk online from abroad” process: enterprise voice services are contracted, invoiced in JOD and installed at an address. No outright ban on non-residents was found, but the practical route for a foreign company is a local entity or branch.
- Jordanian internet providers block calls in messaging apps. This is documented by Freedom House (Freedom on the Net 2018, Jordan): providers block voice calls in WhatsApp, Viber and Skype; the TRC stopped carriers from charging for VoIP in 2016, and the Council of Ministers rejected a proposal to charge JOD 2 a month for unblocking. This does not affect a licensed corporate trunk, but registering the venue's desk phones with a cloud PBX over 5060/UDP is worth testing with a live call on that specific provider before you buy the phones.
- Caller ID spoofing. We found no separate published TRC act; carriers issue numbers under contract and send outbound calls from them. Assume that a third party's number must not be put into the “Show as” field.
- Call recording. The Personal Data Protection Law No. (24) of 2023 applies: it requires explicit, documented (written or electronic) consent to processing personal data. A voice notice about recording at the start of the call is mandatory, in Arabic for a venue in this country.
If it does not work#
- The carrier only delivers the trunk over its own circuit. The most common local cause, and no setting fixes it: Umniah works “through privately managed IP networks”, Mada through a Border Element on the customer's premises. Demand “a SIP trunk over the public internet to our static IP” before signing the contract.
- The trunk does not come up and nobody read the sheet. In Jordan no carrier publishes host, port or mode — the values only come from the provisioning sheet. If the sheet does not state the mode, ask directly: REGISTER or an IP allowlist? With an allowlist the registration checkbox must be cleared, otherwise the trunk will forever read “not registered”.
- A call to the second number is handled by the first number's scenario. The line is matched on the last seven digits. For landline numbers that is exactly the subscriber part and there is no collision, but the mobile numbers
079 1234567and078 1234567merge into one line — separate them with routing rules or do not put them in the same location. - Registration is green but calls do not arrive. Check the form in which the carrier sends the number: it is not documented publicly in Jordan and there are three options (E.164 without the plus, with a leading zero, or the bare subscriber part). Look at the SIP trace in the trunk menu and align the line with what actually arrives.
- Audio is gone in one direction or entirely. Ask about codecs: our PBX speaks G.711 and G.722. A carrier or a reseller may hand over a trunk with G.729 only — then the signalling looks healthy but there is no audio.
- The venue's desk phones will not register with the PBX even though the trunk works. That is the venue's network, not the trunk: Jordanian internet providers filter third-party voice traffic. Try another circuit or ask the provider to confirm that SIP and RTP are not being throttled.
Other common causes are in the general section of the overview; checking the address and port is described in “Check connectivity”.
Frequently asked questions#
Can a Jordanian number be connected to a cloud PBX?#
Yes, if the carrier agrees to deliver the trunk over the public internet to your PBX's static IP. The likeliest candidates are Orange Jordan, Zain and Viacloud: all three advertise a trunk to a third-party PBX as a product. Umniah and Mada describe delivery over their own circuit and through their own device on the premises — such a trunk never reaches the cloud.
Why do Jordanian carriers not publish a host and a port?#
Because they really are not there: neither Orange, nor Zain, nor Umniah, nor Mada, nor Viacloud publishes parameters — they arrive in the provisioning sheet from the engineer. Orange even has a “Check Technical Details” link on its service page, but there is no document behind it. Putting “typical” values into the form is pointless: the trunk will either reject the call or silently fail to come up.
Does the venue need a Jordanian legal entity?#
For a number from a local carrier — in practice yes: a contract, an invoice in JOD and installation at an address. An international aggregator does not solve this: Twilio offers only the toll-free +962 800 for Jordan and requires the owner's address to be outside the country, while Plivo and DIDWW have no Jordanian inbound numbers at all.
Should I take a landline number or a “unified” 079X?#
A landline one. Its subscriber part is exactly seven digits — the same length the line in the PBX matches on, so any incoming format is recognised. A mobile 079X number has eight digits, the first of them is left out of the match, and several such numbers in one location merge into a single line.
Will emergency calls work through such a number?#
No. Jordan's emergency numbers — 911, 191, 199 and the rest — cannot be dialled through our PBX. There must always be an ordinary phone or a mobile on the shift.
Sources#
All links were checked on 9 September 2026.
Carriers
- Orange Jordan — Enterprise “Business Internet & Connectivity → Fixed Services” (SIP Trunk, Basic/Heavy/Premium packages, add-ons, zone tariffs, contacts): https://orange.jo/en/business/enterprise/business-internet-connectivity/fixed-services
- Zain Jordan — Business “Voice Solutions → PRI/SIP Line”: https://www.jo.zain.com/english/Business/Pages/VoiceSolutions_PRILine.aspx
- Umniah — “Fixed Corporate Voice (SIP/PRI)”: https://www.umniah.com/business/voice/corporate-voice/ · Arabic version: https://www.umniah.com/ar/business/voice/corporate-voice/
- Mada Jordan — “الاتصال الصوتي عبر الانترنت” (SIP Trunk, the IP PBX → Border Element → Mada network topology): https://www.mada.jo/pages/Business/EnterpriseSolutions/VoiceSolutions/SIPTrunk
- Viacloud Telecom — “Voice for Business (BusinessSIP)”: https://www.viacloud.com/voice-for-business/
- Damamax — the carrier's website (2008 licence, services, contacts): https://www.damamax.jo/
Regulator and law
- TRC — licensees and numbering section: https://trc.gov.jo/AR/Pages/%D8%A7%D9%84%D9%85%D8%B1%D8%AE%D8%B5_%D9%84%D9%87%D9%85
- TRC via the ITU bulletin — “Jordan (country code +962)”: fixed and mobile numbering ranges by carrier, emergency numbers: https://www.itu.int/dms_pub/itu-t/oth/02/02/T020200006E0008PDFE.pdf
- TRC — “Request for Proposals to provide a Mobile Number Portability solution” (MNP launch at the end of March 2027): https://trc.gov.jo/EBV4.0/Root_Storage/AR/EB_Tenders/MNP_RFP_after_resolving_all_MNOs_comments_after_inserting_dates_21052026_CLEAN.pdf
- Telecommunications Law of Jordan No. 13 of 1995 (English text, WIPO Lex): https://www.wipo.int/edocs/lexdocs/laws/en/jo/jo056en.pdf
- MoDEE — Personal Data Protection Law No. (24) of 2023: https://www.modee.gov.jo/ebv4.0/root_storage/en/eb_list_page/pdpl.pdf
- Freedom House — Freedom on the Net 2018, Jordan (blocking of calls in messaging apps, the 2016–2017 timeline): https://freedomhouse.org/country/jordan/freedom-net/2018
International providers
- Twilio — Jordan: Regulatory Guidelines (toll-free only, address outside Jordan): https://www.twilio.com/en-us/guidelines/jo/regulatory
- Plivo — SIP Trunking Pricing, Jordan (inbound “Not Supported”): https://www.plivo.com/sip-trunking/pricing/jo/
- didlogic — Virtual Phone Numbers for Jordan (national
+962, toll-free0800): https://didlogic.com/virtual-phone-numbers/jordan/ - DIDWW — VoIP termination to Jordan: https://www.didww.com/services/two-way-sip-trunking/outbound-sip-trunking/international-voip-termination/Jordan
- Telnyx — Jordan virtual phone numbers: https://telnyx.com/phone-numbers/jordan · CommPeak — SIP Trunking in Jordan: https://www.commpeak.com/services/sip-trunking/jordan
Related pages#
- Connecting a provider's number to your PBX — the common steps, trunk modes, network requirements and connectivity checks.
- Setting up SIP phones — how to connect desk phones, DECT bases and gateways to extensions.