00 · Header

T7 · SIP, routing, and queues

Queue theory for contact center

Color-coded sequence: Phone → CUBE → Control Hub → PSTN. A packet moves along the arrows. Reduced motion keeps every step visible.

Webex Contact Center routing patterns and Webex Calling hunt-group patterns. The Labs page Erlang model is a Canon study model. It is not estimated wait. Retrieved 2026-10-14.

Room T7-R05 Version v0.1 last-verified: TODO Difficulty L3 Est. time 100–130 min Prereq T3-R03 Reading 16 min

Key takeaways

Skill-based selection filters agents who entirely satisfy the contact or the queue, then applies the pattern. Weights change Best Available scoring. They do not change Longest Available. [cite:1]
Non-skill Longest Available picks the agent available longest since their last contact. An offer on any media drops that position for every channel. A small race can offer two contacts at once because the architecture is distributed. [cite:1]
Circular is round-robin with a pointer, and np2fdx lists it for agent-assignment queues. Top-down always starts at the first configured agent. There is no pointer. [cite:1]
Best Available sums proficiency of the skills in the requirement. A less-than-or-equal skill is scored as 10 minus the value. Boolean, text, and enum skills are not scored. [cite:1]
A Calling hunt group is a different object. Caps in o6rfjeb: Circular, Top Down, and Longest Idle 1,000 agents. Weighted 100. Simultaneous 50. [cite:2]

01 · Executive summary

Four patterns, and no Erlang formula

Skill-based selection filters agents who entirely satisfy the contact or the queue, then applies the pattern. Weights change Best Available scoring. They do not change Longest Available. [cite:1]
Non-skill Longest Available picks the agent available longest since their last contact. An offer on any media drops that position for every channel. A small race can offer two contacts at once because the architecture is distributed. [cite:1]
Circular is round-robin with a pointer, and np2fdx lists it for agent-assignment queues. Top-down always starts at the first configured agent. There is no pointer. [cite:1]
Best Available sums proficiency of the skills in the requirement. A less-than-or-equal skill is scored as 10 minus the value. Boolean, text, and enum skills are not scored. [cite:1]
A Calling hunt group is a different object. Caps in o6rfjeb: Circular, Top Down, and Longest Idle 1,000 agents. Weighted 100. Simultaneous 50. [cite:2]

Why it matters. Longest Idle on a hunt group is not Longest Available on a contact-center queue. The caps and the pointer are the difference you can cite.

02 · Architecture map

Who is eligible, then who is picked

Mermaid source (not rendered)

flowchart LR
  A --> B

03 · Core concepts

What the articles actually select

Eligibility, then pattern

np2fdx: skills and dynamic skills decide who is eligible. The routing pattern picks one agent from that set. [cite:1]

Longest available is cross-media

Agents lose the longest-available position across all channels when they are offered a contact of any media type. [cite:1]

Do not teach the Labs Erlang line as Webex

The Canon labs page labels A=6, N=8, probability of waiting about 0.357, and wait about 32.1 seconds as a study model. np2fdx does not print that formula. Estimated wait in the product is Get Queue Info. This room does not restate a numeric estimated wait. Read nhovcy4 before you teach one. TODO-verify the numeric estimated-wait sentence in this room until that article is open.

Hunt group forwarding

o6rfjeb: when a hunt group receives a call and forwards it to an agent, the agent call-forwarding feature does not work. [cite:2]

Names that are not synonyms

Name	Product	What the article says	Cite
Longest Available	WxCC	Longest time since the last contact, among eligible agents.	[cite:1]
Longest Idle	Calling hunt group	Idle longest. If they do not answer, try the next-longest idle.	[cite:2]
Circular	Both, different caps	WxCC: pointer, agent-assignment in the non-skill section. Hunt group: max 1,000, cycles after the member who took the last call.	[cite:1][cite:2]
Top-down / Top Down	Both	WxCC: always from the top, no pointer. Hunt group: from the top each time, max 1,000.	[cite:1][cite:2]
Best Available	WxCC skill	Highest proficiency score. Not a hunt-group pattern in o6rfjeb.	[cite:1]
Weighted / Simultaneous	Calling hunt group	Weighted max 100, by percent. Simultaneous max 50, all at once.	[cite:2]

04 · Ecosystem & sister technologies

Glossary, map, sisters, edges

Mini map of the neighbors named on this room’s sequence. Orientation sketch, not a new product claim.

Glossary

Longest Available: Eligible agent who has been available the longest since the last contact. [cite:1]
Cross-media position: Any offered media type clears the longest-available position on every channel. [cite:1]
Simultaneous offer: np2fdx: a small possibility that one longest-available agent is routed multiple contacts queued to the same queue at the same time, because the architecture is distributed. [cite:1]
Circular: Round-robin. The pointer moves to the next configured agent after a successful contact-surplus match. Parked contacts do not move that pointer. [cite:1]
Top-down: Every contact starts at the first configured agent and walks down. No pointer. [cite:1]
Best Available: Score from proficiency skills named in the requirement. [cite:1]
Inverted skill: A <= condition uses 10 minus the agent’s value so a lower skill scores as a stronger match. [cite:1]
Weights: Used in Best Available. Not used by Longest Available. [cite:1]
Unscored skills: Boolean, text, and enum skills filter eligibility. They are not in the score. [cite:1]
Skill relaxation: A later requirement overwrites the contact’s skill requirement on a timer so more agents can match. [cite:1]
Call distribution group: Teams at a level. If nobody matches, the contact parks, then the next group’s teams are added. [cite:1]
Capacity-based team: Voice to a DN and a capacity. No Agent Desktop. np2fdx names voicemail, answering machines, or hunt groups as the people or devices that answer. [cite:1]
Default on a team queue: ubg5qd, page header October 08, 2026: for a non-skill queue with team assignment, Longest available is the default. For a non-skill queue with agent assignment, Circular is the default, and that queue can hold a maximum of 1,000 agents. [cite:3]
Hunt group path: Control Hub Services > Calling > Features. [cite:2]
Advance after rings: o6rfjeb: you can enable Advance after a set number of rings for the routing choice. [cite:2]
AutoCSAT skill: nv7abhz, page header October 08, 2026: AutoCSAT can be added as queue routing criteria, alone or with other skills. It is system-controlled. [cite:4]

Mind map

Mermaid source (not rendered)

mindmap
  root((T7-R05))
    Core
    Sisters

Sister-technology matrix

Sister	What it is	Why it matters here	Config touchpoint	Typical failure	Cite
Workforce management	Granular agent states roll out to all Webex Contact Center customers on October 29, 2026.	Adherence groupings must be rebuilt or real-time adherence reporting stops.	New WFM adherence connector. Enabling the feature is optional until that date.	Leaving old state groups in place on the cutover.	[cite:4]
Quality and recording	Calling call recording is not this routing article.	WxCC quality-management retention is not printed in np2fdx.	Read the recording article before a retention number.	TODO-verify any QM retention figure.	[cite:1]
Emergency	Hunt groups and contact-center queues are not the emergency path.	This room does not restate 933.	Read nvfbjts before a WebRTC emergency test.	Teaching a queue pattern as 911 routing.	[cite:2]
Analytics	Routing fairness is not an Analyzer refresh rate.	Do not paste a 5-second figure from another room into this pattern.	Open Analyzer only when the question is a report.	Using a report lag as a routing timer.	[cite:1]
CRM	Screen pop is not a routing pattern.	No parity with Dynamics 365 Contact Center is cited.	TODO-verify connector behavior in this room.	Assuming the CRM chooses the agent.	[cite:1]
AI	AutoCSAT as a dynamic skill for routing.	Administrators add it to queue criteria.	Create Queues, as nv7abhz points.	Hand-entering a CSAT value the page says is system-controlled.	[cite:4]
IVR	upg0eu: an auto attendant provides IVR. A call queue does not. An auto attendant can be used as the IVR in front of a queue.	That is Calling, not Flow Designer.	Put the auto attendant on the DID if you need a menu.	Expecting the queue itself to play a menu.	[cite:5]
Digital and identity	Longest Available position is cleared by chat as well as voice.	Sign-in and SSO are not a routing pattern. Identity behavior for the desktop is TODO-verify here.	Read the desktop room for sign-in.	Treating a social contact as exempt from the position rule.	[cite:1]

Integration map

From	To	Mechanism	What moves	Cite
Flow	Queue	Skill requirement	Eligibility filter.	[cite:1]
Queue	Agent	Longest Available	Longest idle-since-contact among eligible agents.	[cite:1]
Queue	Agent	Best Available	Highest proficiency score.	[cite:1]
Timer	Contact	Skill relaxation	A looser requirement replaces the first.	[cite:1]
Distribution group	Next teams	Expansion	After the park interval, unless availability check expands immediately. This room does not restate the toggle name from a second article.	[cite:1]
Any media offer	Longest-available list	Position reset	All channels.	[cite:1]
Calling hunt group	Members	Pattern plus cap	The five o6rfjeb patterns.	[cite:2]
AutoCSAT	Queue criteria	Dynamic skill	System controlled.	[cite:4]

Cross-platform bridges

Webex behavior	Legacy habit	Peer orientation	Cite
WxCC Longest Available	Calling Longest Idle also looks at time, then moves on if there is no answer. They are not the same sentence.	An Amazon Connect routing profile is TODO-verify.	[cite:1][cite:2]
WxCC Circular pointer	Hunt-group Circular cycles after the member who took the call, max 1,000.	Do not quote 1,000 as a WxCC team size.	[cite:2]
UCCE skill group	Not defined in np2fdx or o6rfjeb.	Selection order inside ICM is TODO-verify.	[cite:1]

Future-integration hooks

Canon plan: T7-R06 puts these objects side by side without inventing a parity matrix.
Personalized AI Routing is on the administrator what’s-new page. This room does not turn that page into a fifth named queue pattern.
Numeric estimated wait stays TODO-verify until nhovcy4 is quoted here.

Ecosystem troubleshooting

Symptom	Likely sister-system cause	Check	Fix	Cite
The same agent gets two chats at once	np2fdx allows a small race on Longest Available when contacts hit one queue together.	The distributed-architecture sentence.	Do not call it a broken pointer until you have ruled that sentence out.	[cite:1]
A voice call makes the agent “newest” for chat	Cross-media position reset.	The any-media sentence.	Expect it.	[cite:1]
Hunt group ignores the agent’s call forward	o6rfjeb says that feature does not work for a hunt-group call.	The create-hunt-group note.	Forward on the group, not on the agent, if the design needs it.	[cite:2]
WFM adherence goes blank on October 29, 2026	State groups were not rebuilt on the new connector.	nv7abhz impact paragraph.	Re-group before or when granular states turn on.	[cite:4]

05 · Flow

One contact, one pattern

Step	From	To	Mechanism	Notes	Cite
1	Contact	Skill filter	Match	Entirely satisfied, or no skills on a non-skill queue.	[cite:1]
2	Pattern	One agent	Longest, circular, top-down, or best	Only the patterns that queue type lists.	[cite:1]
3	Best Available	Score	Proficiency	Invert <= skills. Ignore boolean, text, enum.	[cite:1]
4	Timer	Relaxation	Overwrite	More agents can match.	[cite:1]
5	Group	Expansion	Add teams	After the configured park, in the article’s team example.	[cite:1]
6	Offer	All channels	Reset	Longest-available position.	[cite:1]
7	Calling	Hunt group	Five patterns	Mind the caps.	[cite:2]
8	Labs Erlang	Study model	Not this product	TODO-verify before a numeric estimated wait.	[cite:1]

06 · Config

Where the pattern is chosen

In Contact Center queues, choose the routing pattern the queue type allows. ubg5qd says non-skill team assignment defaults to Longest available. [cite:3]
For skills, set requirements the agent must meet entirely. Add weights only if the pattern is Best Available. [cite:1]
For a Calling hunt group, sign in to Control Hub, go to Services > Calling > Features, and pick one of the five routing options. [cite:2]
If you enable Advance after a set number of rings, that ring count applies to the routing choice. [cite:2]
Leave the Labs Erlang numbers on the labs page. Open nhovcy4 before you teach estimated wait. TODO-verify

07 · Limits

Numbers these articles state

Item	Value	Source	Verified?
Hunt Circular / Top Down / Longest Idle	Max 1,000 agents	[cite:2]	Quoted
Hunt Weighted	Max 100 agents	[cite:2]	Quoted
Hunt Simultaneous	Max 50 agents	[cite:2]	Quoted
Best Available inversion	10 minus the skill value for <=	[cite:1]	Quoted
Circular queue types in the non-skill section	Agent assignment	[cite:1]	Quoted
Granular state rollout	October 29, 2026 for all customers, on the admin what’s-new page	[cite:4]	Quoted
Erlang study model	Not a Webex estimated wait	Canon labs page	Labeled study model
Numeric estimated wait	TODO-verify	nhovcy4 not quoted here	Open
ICM skill-group order	TODO-verify	Not in these articles	Open
QM retention	TODO-verify	Not in np2fdx	Open

08 · Troubleshooting

Failures

Symptom	Likely cause	Evidence	Fix	Cite
Top agents always take the contact	The pattern is top-down. It is supposed to start at the top.	Queue pattern.	Change the pattern if that bias is wrong.	[cite:1]
Circular seems to restart at the first agent	You are on top-down, which has no pointer.	np2fdx contrast sentence.	Confirm the pattern name.	[cite:1]
Best Available ignores a boolean skill in the score	Those skills are eligibility only.	Scoring paragraph.	Use a proficiency skill if you need it in the score.	[cite:1]
Weights did nothing	The pattern is Longest Available.	Weights sentence.	Switch to Best Available or drop the weights.	[cite:1]
Chat waits behind a voice offer	The voice offer cleared the position.	Cross-media sentence.	Expect it.	[cite:1]
Two contacts hit one longest-available agent	The distributed race the article names.	That paragraph.	Do not invent a second cause first.	[cite:1]
Hunt group stops at 51 on simultaneous	The cap is 50.	o6rfjeb.	Shrink the group or pick another pattern.	[cite:2]
Weighted hunt group rejects agent 101	The cap is 100.	o6rfjeb.	Same choice.	[cite:2]
Agent call-forward on a hunt-group call	The article says it does not work.	Create section.	Configure forwarding on the hunt group.	[cite:2]
A fifth WxCC pattern name	np2fdx’s non-skill names in this extract are Longest Available, Circular, and Top-down, plus Best Available on the skill side.	The headings.	Do not add a name the page does not print.	[cite:1]

09 · Self-question ladder

Twelve rungs

L0What does this room refuse to call estimated wait?

The labs Erlang study model.

L1What happens before the routing pattern runs on a skill queue?

Agents must entirely satisfy the skill requirement. [cite:1]

L1Do weights change Longest Available?

No. [cite:1]

L2What clears a longest-available position?

An offer of any media type. [cite:1]

L2Does circular have a pointer?

Yes. Top-down does not. [cite:1]

L2How is a <= skill scored?

10 minus the value. [cite:1]

L3Which skills are not scored?

Boolean, text, and enum. [cite:1]

L3Which non-skill queues does np2fdx list for Circular?

Agent assignment. [cite:1]

L3What is the default pattern ubg5qd names for non-skill team assignment?

Longest available. [cite:3]

L4Hunt-group simultaneous cap?

50 agents. [cite:2]

L4What does a capacity-based team not use?

Agent Desktop. It sends voice to a DN. [cite:1]

L5What is still TODO-verify?

Numeric estimated wait, ICM skill order, QM retention, and peer routing parity.

10 · Lab

Paper lab

Goal: pick a pattern from a written contact, without using the labs Erlang numbers.
Prereq: np2fdx open. No production queue change required.
Step 1. Three eligible agents, idle 9, 4, and 1 minutes since last contact. Pattern Longest Available. Expected: the 9-minute agent.
Step 2. Same agents, top-down order B, A, C, and B is available. Expected: B, even if A has been idle longer.
Step 3. A proficiency skill required as <= 4. Agent value 2. Write the inverted score 8.
Step 4. A hunt group of 60 people that must ring together. Expected: simultaneous’s cap is 50, so the design does not fit.
Evidence: the agent id and the sentence you used.
Break it: apply a weight and keep Longest Available. Recovery: say weights do not apply.
Reflection: which media type would also reset the position.

11 · Quiz

Twelve questions

Q1MCQ

Weights apply to:

Answer

Best Available. Not Longest Available. [cite:1]

Q2MCQ

A chat offer does what to voice longest-available position?

Answer

Clears it. Any media type does. [cite:1]

Q3MCQ

Top-down’s pointer:

Answer

There is no pointer. Every contact starts at the top. [cite:1]

Q4MCQ

Circular in the non-skill section is listed for:

Answer

Agent assignment. [cite:1]

Q5Scenario

Skill value 3 with a <= requirement. Inverted score?

Answer

10 minus 3, so 7. [cite:1]

Q6MCQ

Boolean skills:

Answer

Eligibility only. Not scored. [cite:1]

Q7MCQ

Hunt-group Longest Idle cap:

Answer

1,000 agents. [cite:2]

Q8MCQ

Simultaneous cap:

Answer

50. [cite:2]

Q9MCQ

Default pattern for non-skill team assignment in ubg5qd:

Answer

Longest available. [cite:3]

Q10Scenario

Two contacts reach one longest-available agent together. Which sentence allows a race?

Answer

The distributed-architecture sentence in np2fdx. [cite:1]

Q11Draw

List the five hunt-group patterns and their caps.

Answer

Circular 1000, Top Down 1000, Longest Idle 1000, Weighted 100, Simultaneous 50. [cite:2]

Q12MCQ

The labs Erlang wait is:

Answer

A Canon study model. Not np2fdx estimated wait. Numeric product estimated wait is TODO-verify here.

12 · Audio

Slots for Studio

Transcript slot

Studio fills this. The prompt is the spoken outline, not a second article.

Transcript slot

Studio fills this. The prompt is the spoken outline, not a second article.

Transcript slot

Studio fills this. The prompt is the spoken outline, not a second article.

13 · Interview

Oral answers

30 seconds. WxCC filters on skills, then runs Longest Available, Best Available, Circular, or Top-down as that queue allows. Weights belong to Best Available. [cite:1]

2 minutes. Longest Available is time since the last contact, and any media offer clears it. Circular keeps a pointer. Top-down does not. Best Available inverts a <= skill as 10 minus the value and ignores boolean, text, and enum in the score. [cite:1] A Calling hunt group has different caps, and agent call-forward does not apply to its calls. [cite:2]

30 seconds, what this is not. It is not the labs Erlang model, and it is not an ICM skill group. Those stay marked or labeled.

2 minutes, capacity and AI. A capacity-based team rings a DN. People do not use Agent Desktop. [cite:1] AutoCSAT can be a system-controlled skill on the queue criteria. The what’s-new page header is October 08, 2026. [cite:4]

What you will not say. You will not invent a fifth pattern name.

14 · Citations

Ledger

Retrieved 2026-10-14. Mirrors cites/T7-R05.md.

Understand Routing and Queueing in Webex Contact Center — help.webex — article np2fdx — help.webex.com article np2fdx — retrieved 2026-10-14. Skill filter then pattern. Longest Available including cross-media reset and the distributed race. Circular pointer. Top-down without a pointer. Best Available score, inversion, unscored skill types. Weights. Relaxation. Distribution groups. Capacity-based teams.
Manage hunt groups in Control Hub — help.webex — article o6rfjeb — help.webex.com article o6rfjeb — retrieved 2026-10-14. Five patterns and caps. Path Services > Calling > Features. Agent call forwarding does not work on a hunt-group call. Advance after a set number of rings.
Create queues and configure routing patterns — help.webex — article ubg5qd — help.webex.com article ubg5qd — retrieved 2026-10-14. Non-skill team assignment defaults to Longest available. Non-skill agent assignment defaults to Circular, maximum 1,000 agents. Page header October 08, 2026.
What’s new for administrators in Webex Contact Center — help.webex — article nv7abhz — help.webex.com article nv7abhz — retrieved 2026-10-14. Page header October 08, 2026. AutoCSAT as a dynamic skill. Granular agent states for all customers on October 29, 2026, and the adherence-connector impact.
Comparison of call routing methods — help.webex — article upg0eu — help.webex.com article upg0eu — retrieved 2026-10-14. Auto attendant is the IVR. A call queue is not. An auto attendant can front a queue.

15 · Re-engineer later

Open

Open questions: header date on np2fdx was not in the extract.
Facts still TODO-verify: numeric estimated wait from nhovcy4; ICM skill-group order; QM retention; CRM and identity behavior; peer routing parity.
re-check: none new in the pattern text.
Assets missing: a one-page pattern card, audio.
Next review: np2fdx, o6rfjeb, ubg5qd, nv7abhz.

Sources and go deeper

Checked links were opened this month. A confirm row has no address because that page was not opened.

Wikipedia Webex (Wikipedia) last checked 2026-10
Vendor doc Webex Help Center last checked 2026-10
DevDocs Webex developer documentation last checked 2026-10
DevDocs Webex developer getting started last checked 2026-10
Community Webex community last checked 2026-10
SRND Cisco Collaboration design zone last checked 2026-10
RFC RFC 3261 SIP: Session Initiation Protocol last checked 2026-10
Port table IANA service name and port number registry last checked 2026-10
Port table Port reference for Webex Calling last checked 2026-10
RFC RFC 3263 Locating SIP Servers last checked 2026-10
RFC RFC 3264 An Offer/Answer Model with SDP last checked 2026-10
Wikipedia Session Initiation Protocol (Wikipedia) last checked 2026-10
RFC RFC 3550 RTP last checked 2026-10
RFC RFC 3711 SRTP last checked 2026-10
RFC RFC 4566 SDP last checked 2026-10
RFC RFC 4733 RTP payload for DTMF last checked 2026-10
Wikipedia Real-time Transport Protocol (Wikipedia) last checked 2026-10
Release notes What's new in Webex Calling last checked 2026-10
Vendor doc help.webex.com article np2fdx last checked 2026-10
Vendor doc help.webex.com article o6rfjeb last checked 2026-10
Vendor doc help.webex.com article ubg5qd last checked 2026-10
Vendor doc help.webex.com article nv7abhz last checked 2026-10
Vendor doc help.webex.com article upg0eu last checked 2026-10

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