feat: waku rendezvous spec

standards/core/rendezvous.md

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+---
+title: WAKU-RENDEZVOUS
+name: Waku Rendezvous discovery
+editor: Simon-Pierre Vivier <[email protected]>
+contributors:
+---
+
+## Abstract
+This document describes the goal,
+strategy and usage of the libp2p rendezvous protocol by Waku.
+
+Rendezvous is one of the discovery methods that can be used by Waku.
+It supplements Discovery v5 and Waku peer exchange.
+
+## Background and Rationale
+How do new nodes join the network is the question that discovery answers.
+Discovery must be fast, pertinent and resilient to attacks.
+Rendezvous is both fast and allow the discovery of relevant peers,
+although it design can be easily abused
+due to it's lack of protection against denial of service atacks.
+The properties of rendezvous complements well the slower but safer methods like Discv5.
+To contribute well, a Waku node must know a sufficient number of peers with
+a wide variety of capabilities.
+By using rendezvous in combination with
+[Discv5](https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md#node-discovery-protocol-v5) and
+[Waku peer exchange](https://github.com/waku-org/specs/blob/master/standards/core/peer-exchange.md#abstract),
+Waku nodes will reach a good number of meaningful peers
+faster than through a single discovery method.
+
+## Semantics
+Waku rendezvous fully inherits the [libp2p rendezvous semantics](https://github.com/libp2p/specs/blob/master/rendezvous/README.md#rendezvous-protocol).
+
+## Specifications
+The namespaces used to register and request MUST be in the format `rs/cluster-id/shard`.
+Refer to [RELAY-SHARDING](https://github.com/waku-org/specs/blob/master/standards/core/relay-sharding.md) for cluster and shard information.
+
+Every [Waku Relay](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/11/relay.md) node SHOULD be initialized as a rendezvous point.
+
+Each relay node that participates in discovery
+MUST register with random rendezvous points at regular intervals.
+
+We RECOMMEND a registration interval of  10 seconds.
+The node SHOULD register once for every shard it supports,
+registering only the namespace corresponding to that shard.
+
+We RECOMMEND that rendezvous points expire registrations after 1 minute,
+in order to keep discovered peer records to those recentrly online.
+
+At startup, every Waku node SHOULD discover peers by
+sending requests to random rendezvous points,
+once for each shard it supports.
+
+We RECOMMEND a maximum of 12 peers will be requested each time.
+This number is enough for good GossipSub connectivity and
+minimize the load on rendezvous points.
+
+We RECOMMEND that bootstrap nodes participate in rendezvous discovery and
+that other discovery methods are used in conjunction and 
+continue discovering peers for the lifetime of the local node.
+
+## Future Work
+
+Namespaces will not contain capabilities yet but may in the future. If the need arise nodes could use rendezvous to discover peers with specific capabilities.
+
+# Copyright
+
+Copyright and related rights waived via
+[CC0](https://creativecommons.org/publicdomain/zero/1.0/).
+
+# References
+ - [Discv5](https://github.com/ethereum/devp2p/blob/master/discv5/discv5.md#node-discovery-protocol-v5)
+ - [Peer Exchange](https://github.com/waku-org/specs/blob/master/standards/core/peer-exchange.md#abstract)
+ - [Libp2p Rendezvous](https://github.com/libp2p/specs/blob/master/rendezvous/README.md#rendezvous-protocol)
+ - [Relay](https://github.com/vacp2p/rfc-index/blob/main/waku/standards/core/11/relay.md)