BGP Community Support For GoogleServing Release Beta January 28, 2014 Google Global Cache [email protected] . . . . . . . . . . . . . 2. 3 3 4 4 3 Frequently Asked Questions 7 4 Appendix: Full Reference Table 9 i . . . . . . . . . . . . . . .1 Communities for Indicating Access Technology . . . . . . . . . . . 2. . . . . . . . . . . . . . . . . .Contents 1 Background 1 2 Supported Communities 2. . .2 Communities for Indicating Differentiated Product Offerings . . . . . . . . . . .3 Communities for Indicating Preferred Ingress Point . . . . . . . . . . ii . or a manually configured override agreed upon with our operations teams. for example receiving announcements from a more direct peer. Google will use reasonable efforts to honor the data provided. The same community tags can be used with GGC nodes as well as direct interconnections to AS15169 or AS36040. or policy enforcement. 1 .CHAPTER 1 Background Google supports the exchange of BGP community tags with GGC nodes and peering sessions to signal important properties of a route for reporting. Note: All information in this document is subject to change. load-balancing. All information exchanged should be considered advisory: Google may discard any of this information if it conflicts with a higher-priority policy on the Google network. All communities supported by GGC/Google peerings are in the “15169:” space. to avoid conflict with any communities already in use on your network. and in cases where we receive this signalling it will be considered the highest priority indication of preference. Release Beta 2 Chapter 1. Background .BGP Community Support For Google Serving. though. The currently supported access technology communities are: 3 . From this information. • TCP parameters that may be more optimized for certain classes of connectivity. • Providing performance breakdowns by access technology in the Google Peering portal. In cases where the connectivity level can vary among clients within a subnet. as these will provide the most useful reporting data. the GGC serving system may make determinations about things like: • Buffering parameters in the stream sent to the client (controlling the amount that the server over-sends to the client with the goal of minimizing the number of bytes wasted in serving to the client while maintaining a high-quality user experience).CHAPTER 2 Supported Communities 2. Google encourages providing specific announcements that cover only a single access technology per block.1 Communities for Indicating Access Technology The GGC software currently supports communities that will indicate the class of connectivity that clients have in the last mile. the provider should advertise all applicable technologies available to that subnet. In order for reporting to be provided. 4 Chapter 2. The range for product differentiation is 15169:11000 .1: Access Technology Communities Community 15169:10010 15169:10020 15169:10030 15169:10040 15169:10050 15169:10060 15169:10070 15169:10080 15169:10090 15169:10100 15169:10110 15169:10120 15169:10130 15169:10140 15169:10150 15169:10160 15169:10170 Access Technology GPRS Mobile Broadband 2. Google has chosen to not use MEDs to reflect the fact that these policies are not routing-level priorities: they are advisory and they can span multiple different interconnection types with Google. this is meant as a distinction to refer to an access product marketed towards business customers. a group of communities is provided to help distinguish between them.google. 15169:13300 indicates the highest preference while 15169:13000 is the lowest priority. 15169:13200 is assumed as the priority. In the event that an ISP offers a differentiated offering using the same access type.com product editor by matching against access technologies: if a company offers a Fiber and a DSL product they can setup each as an independent product in the product editor. Multiple egress-points can share the same preference and in this case Google will treat as being equally good choices from the perspective of the peer network.BGP Community Support For Google Serving.3 Communities for Indicating Preferred Ingress Point Google allows peers and ISPs hosting GGC servers to send advisory data indicating preference about traffic ingress point into their networks.Not directly user-facing Satellite For any technologies that specify Business.5G/Edge Mobile Broadband 3G Mobile Broadband 4G Mobile Broadband Dial-Up ISDN Cable Cable-Business Ethernet/Enterprise Access Fiber to the Home Fiber to the Premises-Business ADSL ADSL-Business VDSL VDSL-Business Wholesale/Transit. 2.15169:11005. Products can be built inside the peering. Release Beta Table 2. Performance reporting is available on a per-product basis.2 Communities for Indicating Differentiated Product Offerings Google provides the ability for providers to get performance reporting by product. though Google will attempt to honor this signal between equally good routes. In the case that no tag is applied. 2. There are a number of other signals that Google takes into account when making trafficrouting decisions that may override this preference. the prefixes must also be tagged with an access technology community. The supported communities are: • 15169:13000-13300: preference for receiving traffic at a particular ingress point for a particular block. Supported Communities . In all cases they are advisory only to express desired intent in terms of ingress traffic delivery. Attempt to serve traffic on an indirect path (through other upstreams or peers) before using this prefix.2: Preferred Ingress Signalling Communities Community 15169:13000 . Any prefix tagged in this range is preferred over indirect paths but not preferred to an interconnection point where the prefix is untagged. Default priority to receive traffic for this prefix at this interconnection point (the same as if the prefix is untagged). When preference is expressed across different deployment types or different peer ASNs. 15169:13001 . Default priority of traffic on an indirect path. While Google will make a best-effort attempt to deliver traffic in accordance with these preferences.15169:13099 indicate very low preference (the higher the tag the higher the preference)... Table 2..3.. Highest preference to receive traffic for this prefix at this interconnection point (try to serve traffic here). 15169:13201 . 15169:13100 . 15169:13200 .. 2. they will be treated globally across all inbound traffic to a particular ASN. Tagging with this community indicates that the preference is equal to receiving traffic over an indirect path.BGP Community Support For Google Serving. the decision of how to egress traffic from our networks takes many factors into account and may not reflect stated preference. 15169:13300 Preferred Ingress Signalling Range Lowest preference to receive traffic for this prefix at this interconnection point (try to not serve traffic here). 15169:13101 . Release Beta The same community tags can be used with GGC nodes as well as direct interconnections to AS15169 or AS36040..15159:13199 indicate low preference. Any prefix tagged in this range is less preferred than an indirect path. Communities for Indicating Preferred Ingress Point 5 .15169:13299 indicate high preference (the higher the tag the higher the preference). BGP Community Support For Google Serving. Release Beta 6 Chapter 2. Supported Communities . we will assume that all communities received on any session apply (since multiple access communities can be supplied on any prefix). • For preferred-ingress signalling. 7 . we will assume that all communities received on any session apply (since multiple access communities can be supplied on any prefix). Q: What happens if Google receives a community in one place. The differentiation allows you to specify which session has a high or low preference for serving a particular block. but not another? A: This depends on the community: • For access technology communities. • For preferred-ingress signalling. any prefix that does not have a community is assumed to have the default priority: 15169:13200.CHAPTER 3 Frequently Asked Questions Q: What happens if Google receives inconsistent communities on the same prefix in multiple locations (GGC nodes and/or PNIs)? A: This depends on the community: • For access technology communities. differing communities on different sessions is intended. BGP Community Support For Google Serving. Frequently Asked Questions . Release Beta 8 Chapter 3. Not directly user-facing Satellite Community 15169:11000 .. 15169:11005 Product Differentiation Community Product Differentiator #1 Product Differentiator #2 ..CHAPTER 4 Appendix: Full Reference Table Community 15169:10010 15169:10020 15169:10030 15169:10040 15169:10050 15169:10060 15169:10070 15169:10080 15169:10090 15169:10100 15169:10110 15169:10120 15169:10130 15169:10140 15169:10150 15169:10160 15169:10170 Access Technology Range GPRS Mobile Broadband 2.5G/Edge Mobile Broadband 3G Mobile Broadband 4G Mobile Broadband Dial-Up ISDN Cable Cable-Business Ethernet/Enterprise Access Fiber to the Home Fiber to the Premises-Business ADSL ADSL-Business VDSL VDSL-Business Wholesale/Transit.#5 Product Differentiator #6 9 . .15169:13099 indicate very low preference (the higher the tag the higher the preference). 15169:13001 . 15169:13200 . Any prefix tagged in this range is less preferred than an indirect path. 15169:13101 .BGP Community Support For Google Serving. Release Beta Community 15169:13000 . Appendix: Full Reference Table .... 15169:13201 . Any prefix tagged in this range is preferred over indirect paths but not preferred to an interconnection point where the prefix is untagged.15159:13199 indicate low preference. Highest preference to receive traffic for this prefix at this interconnection point (try to serve traffic here). Default priority to receive traffic for this prefix at this interconnection point (the same as if the prefix is untagged). Chapter 4.. 15169:13300 10 Preferred Ingress Signalling Range Lowest preference to receive traffic for this prefix at this interconnection point (try to not serve traffic here). Default priority of traffic on an indirect path. 15169:13100 . Tagging with this community indicates that the preference is equal to receiving traffic over an indirect path.. Attempt to serve traffic on an indirect path (through other upstreams or peers) before using this prefix.15169:13299 indicate high preference (the higher the tag the higher the preference).