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Twilio models a SIP trunk as a container (trunking.v1.trunks) that you decorate with origination URLs, credential lists, and IP access control lists — but the credential lists and IP ACLs actually live in a different API namespace (api.v2010.account.sip.*) and are only associated with the trunk by SID. Vobiz collapses that split: every trunking concept is a first-class, typed SDK resource — trunks, credentials, ip_access_control_list, and origination_uri — all account-scoped by an explicit auth_id. Migration is a resource-for-resource rename plus dropping the cross-namespace association dance.
AUTH_ID is your Vobiz Auth ID (MA_…) and AUTH_TOKEN your Auth Token. In the Vobiz SDK, api_key is the Auth ID (sent as X-Auth-ID) and auth_token is sent as X-Auth-Token. Every trunking method takes auth_id explicitly. Base URL: https://api.vobiz.ai/api/v1.

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Twilio → Vobiz mapping

Twilio (Elastic SIP Trunking)VobizNotes
client.trunking.v1.trunks.create()client.trunks.create_trunk(auth_id, name=, trunk_type=, max_concurrent_calls=)The trunk container. trunk_type is "INBOUND" / "OUTBOUND".
client.trunking.v1.trunks.list()client.trunks.list_trunks(auth_id)List every trunk on the account.
client.trunking.v1.trunks(sid).fetch()client.trunks.retrieve_trunk(auth_id, trunk_id=)Fetch one trunk.
client.trunking.v1.trunks(sid).update(...)client.trunks.update_trunk(auth_id, trunk_id=, name=, max_concurrent_calls=, enabled=)Rename, re-cap concurrency, enable/disable.
client.trunking.v1.trunks(sid).delete()client.trunks.delete_trunk(auth_id, trunk_id=)Remove the trunk.
Concurrent-call channels (account/CPS limits)max_concurrent_calls= on the trunkConcurrency is set directly on each Vobiz trunk.
sip.credential_lists.create() + .credentials.create(username, password) + trunks(sid).credentials_lists.create(credential_list_sid)client.credentials.create_credential(auth_id, username=, password=)One typed call — no separate list object to create and then associate.
sip.credential_lists(cl).credentials.list()client.credentials.list_credentials(auth_id)List SIP credentials.
sip.credential_lists(cl).credentials(cr).update(password=)client.credentials.update_credential(auth_id, credential_id=, password=)Rotate a password.
sip.credential_lists(cl).credentials(cr).delete()client.credentials.delete_credential(auth_id, credential_id=)Delete a credential.
sip.ip_access_control_lists.create() + .ip_addresses.create(ip_address) + trunks(sid).ip_access_control_lists.create(ip_access_control_list_sid)client.ip_access_control_list.create_ip_acl(auth_id, name=, ip_address=)IP-based termination auth in one call.
sip.ip_access_control_lists(al).ip_addresses.list()client.ip_access_control_list.list_ip_acls(auth_id)List allowed source IPs.
ip_access_control_lists(al).ip_addresses(ip).update(...)client.ip_access_control_list.update_ip_acl(auth_id, ip_acl_id=, ...)Change an allowed IP.
ip_access_control_lists(al).ip_addresses(ip).delete()client.ip_access_control_list.delete_ip_acl(auth_id, ip_acl_id=)Revoke an IP.
client.trunking.v1.trunks(sid).origination_urls.create(weight, priority, enabled, friendly_name, sip_url)client.origination_uri.create_origination_uri(auth_id, name=, sip_uri=, priority=)Where inbound (origination) calls are delivered.
origination_urls.list()client.origination_uri.list_origination_uris(auth_id)List origination endpoints.
origination_urls(ou).update(...)client.origination_uri.update_origination_uri(auth_id, origination_uri_id=, ...)Repoint or re-prioritise.
origination_urls(ou).delete()client.origination_uri.delete_origination_uri(auth_id, origination_uri_id=)Remove an endpoint.
disaster_recovery_url on the trunkA second origination_uri with a higher priority numberAdd fallback SBCs as lower-priority origination URIs — Vobiz walks them in priority order.
client.incoming_phone_numbers(sid).update(trunk_sid=...)client.phone_numbers.assign_number_to_trunk(auth_id, phone_number=, trunk_group_id=)Route a purchased DID’s inbound calls through the trunk.
Detach number from trunkclient.phone_numbers.unassign_number_from_trunk(auth_id, phone_number=)Stop routing a DID through the trunk.
Account SID + Auth Token (HTTP Basic)X-Auth-ID + X-Auth-Token headers (set once on the client)
trunking.twilio.com/v1https://api.vobiz.ai/api/v1Trunking and voice share one Vobiz base URL.
Trunk-call CDRs (Voice Insights / call logs)client.cdr.list_cdrs(auth_id, sip_call_id=, from_number=, to_number=, start_date=, end_date=, ...)Query completed trunk calls, including by SIP Call-ID.

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Create a trunk

Termination (outbound) and origination (inbound) both hang off one trunk object. In Vobiz you also set the concurrency cap right here. 
from twilio.rest import Client

client = Client(ACCOUNT_SID, AUTH_TOKEN)

trunk = client.trunking.v1.trunks.create(
    friendly_name="My Outbound Trunk",
    domain_name="my-company.pstn.twilio.com",
)
print(trunk.sid)

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Termination auth — credentials and IP allow-lists

This is where the biggest simplification lands. On Twilio you create a credential list in the api.v2010 namespace, add credentials to it, then make a second call to associate the list’s SID with the trunk. Vobiz creates the credential (and the IP rule) as one typed call against the account. 
# 1) create the credential list, 2) add a credential, 3) associate with trunk
cl = client.api.v2010.account.sip.credential_lists.create(
    friendly_name="Termination Users",
)
client.api.v2010.account.sip \
    .credential_lists(cl.sid) \
    .credentials.create(username="pbx01", password="S3cur3Pass!")

client.trunking.v1.trunks(trunk.sid) \
    .credentials_lists.create(credential_list_sid=cl.sid)
Prefer IP-based authentication for a static SBC? Same story — one call instead of three: 
al = client.api.v2010.account.sip.ip_access_control_lists.create(
    friendly_name="Datacenter SBCs",
)
client.api.v2010.account.sip \
    .ip_access_control_lists(al.sid) \
    .ip_addresses.create(friendly_name="SBC-1", ip_address="203.0.113.10")

client.trunking.v1.trunks(trunk.sid) \
    .ip_access_control_lists.create(ip_access_control_list_sid=al.sid)

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Origination — where inbound calls are delivered

Twilio’s origination URLs carry weight + priority + enabled. Vobiz’s origination_uri carries a priority; add multiple URIs to get ordered failover (the lowest priority number is tried first), which is exactly how you’d replace a disaster_recovery_url. 
client.trunking.v1.trunks(trunk.sid).origination_urls.create(
    friendly_name="Primary SBC",
    sip_url="sip:sbc1.example.com",
    priority=10,
    weight=10,
    enabled=True,
)
client.trunking.v1.trunks(trunk.sid).origination_urls.create(
    friendly_name="Backup SBC",
    sip_url="sip:sbc2.example.com",
    priority=20,   # higher number = tried after primary
    weight=10,
    enabled=True,
)

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Route a DID through the trunk

Once the trunk is provisioned, point a purchased number at it so inbound PSTN calls follow your origination URIs. 
number = client.incoming_phone_numbers.list(phone_number="+14155551234")[0]
client.incoming_phone_numbers(number.sid).update(trunk_sid=trunk.sid)

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Key differences

  • Every trunking concept is a typed, top-level SDK resource. trunks, credentials, ip_access_control_list, and origination_uri are first-class clients with full CRUD — no reaching into a separate api.v2010.account.sip.* namespace and then associating SIDs back to the trunk.
  • One call for termination auth. Creating a SIP credential (or an IP rule) is a single create_credential / create_ip_acl call, versus Twilio’s create-list → add-item → associate-with-trunk three-step.
  • Concurrency lives on the trunk. max_concurrent_calls is a plain field on create_trunk/update_trunk, so capacity is explicit per trunk and editable in place.
  • Disaster recovery is just priority. Add lower-priority origination_uri entries and Vobiz walks them in order — the same fallback behaviour as Twilio’s disaster_recovery_url, expressed with the resource you already use for origination.
  • Consistent account scoping. Every method takes auth_id explicitly, so multi-account and sub-account trunk management is uniform across trunks, credentials, origination_uri, and number assignment.
  • Auth is header-based. Set X-Auth-ID + X-Auth-Token once on the client instead of HTTP Basic on each request; the same client also drives voice, numbers, and CDRs.
  • Trunk-call visibility via CDRs. client.cdr.list_cdrs(auth_id, sip_call_id=…) lets you query completed trunk calls — including by SIP Call-ID — from the same SDK.
Migrating call-control flows too? <Gather> covers your IVR menus. See the full Twilio → Vobiz overview for the migration order across trunking, numbers, and voice.