Setting up a Bandwidth SIP trunk

See also

Sources

1. 1
   With Proxy Hot Swap enabled on an AudioCodes Proxy Set, the device automatically retries a failed message against a redundant proxy in the set.

   Configuring Proxy Sets - Mediant Software SBC User's Manual Version 7.4 · Configuring Proxy Sets, Proxy Hot Swap parameter · Checked 2026-09-30
2. 2
   An AudioCodes Proxy Set can run Proxy Keep-Alive using SIP OPTIONS sent at a user-defined interval, and up to three SIP response codes can be configured as keep-alive failure responses that mark the proxy offline.

   Configuring Proxy Sets - Mediant Software SBC User's Manual Version 7.4 · Configuring Proxy Sets, Proxy Keep-Alive and Keep-Alive Failure Responses parameters · Checked 2026-09-30
3. 3
   On an AudioCodes Mediant SBC a Proxy Set defines the address (IP address or FQDN) and transport type of a SIP server, the transport is selectable per proxy address from UDP, TCP, TLS and SCTP, and the Proxy Set is the destination assigned to an IP Group.

   Configuring Proxy Sets - Mediant Software SBC User's Manual Version 7.4 · Configuring Proxy Sets, introduction and Proxy Address table Transport Type · Checked 2026-09-30
4. 4
   An AudioCodes Proxy Set's redundancy mode is either Parking, where the device stays with a proxy until it fails, or Homing, where the device always tries to use the highest-priority proxy that is online.

   Configuring Proxy Sets - Mediant Software SBC User's Manual Version 7.4 · Configuring Proxy Sets, Redundancy Mode parameter · Checked 2026-09-30
5. 5
   For outbound caller ID on the voice trunk Bandwidth reads the From field, a Remote-Party-ID header takes precedence when present, P-Asserted-Identity and Privacy headers are also supported, and the number must be in E.164 format.

   UC trunking integration guide · Features section, Caller ID In/Out · Checked 2026-09-30
6. 6
   A third-party SBC vendor article states that G.711 A-law is universally available on Bandwidth trunks, which Bandwidth's own UC trunking codec list does not include.disputed

   Bandwidth.com SBC Integration · Codecs section · Checked 2026-09-30
7. 7
   Cisco advises against catch-all dial-peer patterns such as destination-pattern .T on CUBE and recommends routing only known phone number ranges or SIP URIs, because generic patterns raise the likelihood of routing a fraudulent call.

   Cisco Guide to Harden Cisco Unified Border Element (CUBE) Enterprise Devices · Toll-fraud prevention, dial-peer patterns · Checked 2026-09-30
8. 8
   By default CUBE silently discards an inbound call that fails the IP trusted list check; no silent-discard untrusted makes it return an error instead, which Cisco cautions can reveal that the device listens for SIP.

   Cisco Guide to Harden Cisco Unified Border Element (CUBE) Enterprise Devices · Toll-fraud prevention, silent-discard untrusted · Checked 2026-09-30
9. 9
   By default Cisco CUBE trusts inbound connections from the IPv4 and IPv6 addresses configured as dial-peer session targets and in voice class server-groups; further addresses are added with the ip address trusted list command under voice service voip.

   Cisco Guide to Harden Cisco Unified Border Element (CUBE) Enterprise Devices · Toll-fraud prevention, IP address trusted list · Checked 2026-09-30
10. 10
    Bandwidth documents a SIP Authentication (network bridge) option in which a realm and SIP credentials are created under Account > SIP Credentials, the first INVITE is challenged with a 407, and the INVITE is resent with a Proxy-Authorization header.disputed

    SIP Authentication (network bridge) setup and configuration · Realm Creation, SIP Credentials Creation and call-flow sections · Checked 2026-09-30
11. 11
    A Dynamic Location Routing 911 test call has the same parameters and flow as the 933 call except that the user part of the request URI is 911; while the account is in testing the call can be sent without connecting to the PSAP and is rejected, and Bandwidth can confirm the SIP request was correct.

    E911 Dynamic Location Routing integration and testing guide · 911 test calls section · Checked 2026-09-30
12. 12
    Sending Dynamic Location Routing location by value (a PIDF-LO attachment in the INVITE) requires TCP, because the attachment is likely to make the INVITE too large for a UDP packet, and the address sent must exactly match the standardized address Bandwidth returned at validation.

    E911 Dynamic Location Routing integration and testing guide · Location by Value section · Checked 2026-09-30
13. 13
    A Dynamic Location Routing endpoint requires PIDFLOEnabled set to true, an Identifier of 10 to 30 alphanumeric characters that matches the SIP INVITE exactly, a 10-digit NANPA-valid CallbackNumber, and a CallerName of at most 50 characters; PreferredLanguage is optional and defaults to English.

    E911 Dynamic Location Routing integration and testing guide · Endpoints section, attribute table · Checked 2026-09-30
14. 14
    With E911 Dynamic Location Routing every geolocation must be prevalidated and added to the Bandwidth App before a call uses it.

    E911 Dynamic Location Routing integration and testing guide · Geolocations section · Checked 2026-09-30
15. 15
    A Dynamic Location Routing endpoint identifier must be unique across Bandwidth; entering one already used on another Bandwidth App account returns an error.

    E911 Dynamic Location Routing integration and testing guide · Endpoints section, uniqueness note · Checked 2026-09-30
16. 16
    Bandwidth recommends Location by Reference for Dynamic Location Routing: the INVITE carries a Geolocation header whose URL is https://emergency.bandwidth.com/locations/ followed by the account number and the location reference, which keeps the INVITE small enough for UDP.

    E911 Dynamic Location Routing integration and testing guide · Location by Reference section · Checked 2026-09-30
17. 17
    A newly created or updated Dynamic Location Routing geolocation may take several seconds or several minutes to propagate to Bandwidth's 911 call processing servers.

    E911 Dynamic Location Routing integration and testing guide · Geolocations section, propagation note · Checked 2026-09-30
18. 18
    Bandwidth supports both in-band DTMF and out-of-band DTMF as described in RFC 2833.

    PBX integration guide · DTMF statement · Checked 2026-09-30
19. 19
    Bandwidth's UC trunking guide specifies E.164 number format with a leading plus sign, for example +19192971100.

    UC trunking integration guide · Attributes section, Dial Plans · Checked 2026-09-30
20. 20
    Dialing 933 reaches a Bandwidth text-to-speech service that reads back the calling phone number and its provisioned address; the static E911 guide limits it to one call per minute and describes it as a courtesy check rather than full verification.

    E911 for Static VoIP integration & testing guide · 933 testing service section · Checked 2026-09-30
21. 21
    Because static E911 binds one address to each phone number while Dynamic Location Routing supplies the location in the INVITE at call time, static provisioning suits numbers used at one fixed place and Dynamic Location Routing suits devices that move between places.inferred

    E911 Dynamic Location Routing integration and testing guide · Location method sections read together with the static E911 configuration article · Checked 2026-09-30
22. 22
    When a Bandwidth 911 SBC answers with SIP 410 the customer must resend the INVITE to the other 911 SBC, and must not fail over on a 487, which is the normal response to the customer's own CANCEL.

    E911 for Static VoIP integration & testing guide · Failover handling and response codes section · Checked 2026-09-30
23. 23
    For a live 911 test call Bandwidth tells customers to schedule it in advance through the PSAP's non-emergency number, to state at once that the call is a test and not an emergency, and to avoid lunch hours and 4:00 to 6:00 p.m. local time.

    E911 for Static VoIP integration & testing guide · 911 test call rules section · Checked 2026-09-30
24. 24
    For Bandwidth 911 calls UDP ports 1024 to 64000 should be open for RTP media.

    E911 for Static VoIP integration & testing guide · Media/audio section · Checked 2026-09-30
25. 25
    For 911 traffic Bandwidth supports up to 10 customer source IP addresses by default; ranges must be listed as individual addresses, DNS entries are not supported, and additional IPs need approval and incur extra charges.

    E911 for Static VoIP integration & testing guide · SIP peer IP configuration section · Checked 2026-09-30
26. 26
    Static E911 is configured in the Bandwidth App under Emergency > E911 Phone Numbers > Add by entering the phone numbers or uploading a CSV, a caller name, and a geolocation address, then clicking Add Phone Numbers.

    How do I configure E911 service for my phone numbers in the Bandwidth App? · Steps 1 to 6 · Checked 2026-09-30
27. 27
    On a static E911 call Bandwidth looks for the calling number in P-Asserted-Identity (if enabled), then Remote-Party-ID, then From; if none carries one the call gets a generic callback number and is routed to the Emergency Call Center unless unprovisioned calls are denied.

    E911 for Static VoIP integration & testing guide · SIP headers and caller ID section · Checked 2026-09-30
28. 28
    For static E911 Bandwidth supports only the G.711 u-law codec, and 911 calls offered with other codecs may fail to establish.

    E911 for Static VoIP integration & testing guide · Supported codecs section · Checked 2026-09-30
29. 29
    The static E911 guide gives simulated-failover test calling numbers: 15555558888 when the primary 911 route is ATL and 15555559999 when the primary is DFW.

    E911 for Static VoIP integration & testing guide · Simulated failover testing section · Checked 2026-09-30
30. 30
    On the static E911 connection SIP REFER is not supported (re-INVITE is used instead), SIP registration and authentication must be disabled, and OPTIONS messages are supported but should be sent no more than once in a 60-second period.

    E911 for Static VoIP integration & testing guide · SIP configuration requirements · Checked 2026-09-30
31. 31
    Bandwidth provides two geographically redundant SBCs for 911 calls, and the customer configures them as primary and secondary or as round-robin targets.

    E911 for Static VoIP integration & testing guide · Session Border Controllers (SBCs) section · Checked 2026-09-30
32. 32
    Test calls from an unprovisioned phone number are not permitted unless Bandwidth Support allows them in advance, and they may be charged under the customer's contract.

    E911 for Static VoIP integration & testing guide · Unprovisioned call handling section · Checked 2026-09-30
33. 33
    Bandwidth asks customers to be able to fail over to its geo-redundant access point on a variety of SIP error codes when the primary access point is unavailable.

    PBX integration guide · Failover statement · Checked 2026-09-30
34. 34
    A Location's Voice settings include a Failover URI field that accepts a SIP address or a phone number.

    Managing Locations in the Bandwidth App · Origination Settings section, Failover URI · Checked 2026-09-30
35. 35
    A Bandwidth account is organised as Account, then Sub-account (called Site in the API), then Location (called SIP Peer in the API), with phone numbers assigned to a Location and Sub-account.

    Structure · Structure page, hierarchy and terminology sections · Checked 2026-09-30
36. 36
    Bandwidth's PBX integration guide states that Bandwidth does not use a username and password to authenticate trunk traffic and authenticates only by trusted IP.disputed

    PBX integration guide · Registration and authentication statement · Checked 2026-09-30
37. 37
    Bandwidth's integration guides do not publish the trunk proxy IP addresses; the customer obtains them from their Bandwidth Implementation Specialist or Bandwidth Support.

    UC trunking integration guide · IP Information section · Checked 2026-09-30
38. 38
    A Location is created under Account > Locations > Add Location by entering a Name, an optional Description, the Sub-Account it belongs to and an optional Default Location toggle, then clicking Create Location.

    Managing Locations in the Bandwidth App · Creating a Location section · Checked 2026-09-30
39. 39
    A Location can be deleted only after every phone number has been removed from it, by moving the numbers elsewhere or disconnecting them.

    Managing Locations in the Bandwidth App · Deleting a Location section · Checked 2026-09-30
40. 40
    Bandwidth presents a mated pair of signaling proxies: the customer must allow inbound signaling from both addresses, because a call may arrive from either, and must configure both as outbound targets so calls continue if one is offline.

    UC trunking integration guide · IP Information section · Checked 2026-09-30
41. 41
    47 CFR 9.16 requires a multi-line telephone system to let a user directly initiate a call to 911 from any station without dialing any additional digit, code, prefix or post-fix, and requires a notification initiated contemporaneously with the 911 call that does not delay it.

    47 CFR § 9.16 - General obligations for MLTS (Cornell LII republication) · 47 CFR 9.16(a) and (b)(1)-(2) · Checked 2026-09-30
42. 42
    47 CFR 9.16 requires automated dispatchable location for on-premises fixed MLTS telephones from 6 January 2021, and from 6 January 2022 requires it for non-fixed and off-premises devices when technically feasible, otherwise allowing end-user manual update or alternative or enhanced location information.

    47 CFR § 9.16 - General obligations for MLTS (Cornell LII republication) · 47 CFR 9.16(b)(3) · Checked 2026-09-30
43. 43
    Up to 5000 NANP phone numbers can be moved at once between accounts, Sub-accounts and Locations from Numbers > My Numbers > Actions, by a user holding the Configuration or Line Features role, provided the accounts share a Global Account Number.

    Moving phone numbers in the Bandwidth App · Prerequisites and Option 1 and Option 2 steps · Checked 2026-09-30
44. 44
    When numbers are moved in the Bandwidth App the operator must choose whether the numbers' E911 configuration is migrated or deleted, and Bandwidth warns that moving numbers to another account may cause service disruption.

    Moving phone numbers in the Bandwidth App · Move steps, E911 configuration step and warning · Checked 2026-09-30
45. 45
    Bandwidth UC trunking does not support SIP registration; the customer must present public static IP addresses.

    UC trunking integration guide · No Registration section · Checked 2026-09-30
46. 46
    A phone number added to a Location inherits the settings and properties of that Location.

    How do I set up my Bandwidth App account? · Locations section · Checked 2026-09-30
47. 47
    On the Legacy North American Platform numbers are ordered under Numbers > Buy Numbers by choosing Regular or Toll-free, searching, selecting numbers, and on the Place & Purchase page choosing the required Sub-account and Location before clicking Purchase.

    Searching and ordering phone numbers on the Legacy North American Platform · Steps to begin your order and Selection and checkout sections · Checked 2026-09-30
48. 48
    On the Universal Platform numbers are ordered under Numbers > Buy Numbers by choosing a contracted country and number type, searching, selecting numbers, assigning a Sub-account and Location on the Place & Purchase page with an optional Voice Configuration Package and Requirements Package, then clicking Purchase and Confirm Purchase.

    Searching and ordering phone numbers on the Universal Platform · Ordering steps 1 to 10 · Checked 2026-09-30
49. 49
    Inbound (origination) delivery is configured on the Location's Voice tab in the field Voice IP addresses / DNS hosts, which takes the customer endpoint IP address or DNS host.

    Managing Locations in the Bandwidth App · Origination Settings section · Checked 2026-09-30
50. 50
    One SBC vendor's Bandwidth integration article recommends defining one peer entry per Bandwidth proxy address, enabling SIP OPTIONS heartbeats toward both, ordering routes so traffic advances to the second address when the first stops responding, and dropping inbound SIP from every source other than the two Bandwidth addresses.field report

    Bandwidth.com SBC Integration · NAP, SIP OPTIONS keepalive, failover and access-control sections · Checked 2026-09-30
51. 51
    A Sub-account is created in the Bandwidth App under Account > Sub-Accounts by completing the required fields and clicking Create Sub-Account.

    How do I manage Sub-accounts in the Bandwidth App? · Creating a Sub-account section · Checked 2026-09-30
52. 52
    A Sub-account can be deleted only after all Locations have been removed from it; the control is Delete Sub-Account under Account > Sub-Accounts.

    How do I manage Sub-accounts in the Bandwidth App? · Deleting a Sub-account section · Checked 2026-09-30
53. 53
    Every Bandwidth account must have at least one Sub-account, and Bandwidth recommends separate Sub-accounts for development and production.

    How do I set up my Bandwidth App account? · Sub-accounts section · Checked 2026-09-30
54. 54
    Bandwidth publishes a separate Dynamic E911 for Microsoft Teams guide in which the SBC must support TCP on port 5060, emergency addresses are configured in Teams, and endpoints are provisioned in the Bandwidth App.

    Dynamic E911 for Microsoft Teams integration and testing guide · Overview and SBC requirements · Checked 2026-09-30
55. 55
    Customers contracted for the Unified Communications (UC) product enter the IPs that send outbound calls in the Location's Termination hosts field; other customers must open a support ticket to have their IPs whitelisted.

    Managing Locations in the Bandwidth App · Termination Settings section · Checked 2026-09-30
56. 56
    A Location's Traffic Distribution Mechanism offers None (one IP), Random (up to 10 IPs) and Sequential failover (up to 10 IPs, tried in the order entered).

    Managing Locations in the Bandwidth App · Origination Settings section, Traffic Distribution Mechanism · Checked 2026-09-30
57. 57
    Bandwidth's UC trunking guide lists G.711 u-law and G.729a as fully supported codecs and iLBC as supported inbound only.

    UC trunking integration guide · Attributes section, Supported Codecs · Checked 2026-09-30
58. 58
    For the voice trunk, UDP port 5060 must be open for SIP signaling and UDP ports 1024 to 65534 must be open, statically or dynamically through an ALG, for audio.

    UC trunking integration guide · Ports to be Opened section · Checked 2026-09-30
59. 59
    Bandwidth requires all SIP and audio on the trunk to be delivered over UDP in packets no larger than 1350 bytes; TCP is not supported.

    PBX integration guide · Transport protocol statement · Checked 2026-09-30

Documents

Cite this page

WarmTransfer. (2026, September 30). Setting up a Bandwidth SIP trunk. WarmTransfer. https://warmtransfer.net/guides/bandwidth-sip-trunk-setup

@misc{warmtransfer-bandwidth-sip-trunk-setup,
  title  = {Setting up a Bandwidth SIP trunk},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/guides/bandwidth-sip-trunk-setup},
  note   = {Verified 2026-09-30}
}